Upper extremity fusion devices and methods

ABSTRACT

A fusion implant and fusion members for fusing target bones of an upper extremity. The fusion implant including internally threaded apertures of a first thread lead, and the fusion members including threading of the first thread lead and threading of a second thread lead that is less than the first thread lead. The fusion implant and a targeting instrument being configured to couple to one another in a predefined orientation. The predetermined orientation resulting in alignment of aspects of the fusion implant with aspects of the targeting instrument. A guide clamp for facilitating forming of an implant cavity in adjacent bones for implantation of the fusion implant therein. A surgical method for facilitating fusion of adjacent target bones utilizing a fusion implant, fusion members, a targeting instrument and a guide clamp to reduce space between the adjacent bones such that they at least abut one another.

FIELD OF THE INVENTION

The present invention relates to the field of fixation of anatomicalstructures, and, in particular, to devices, methods and instrumentationfor facilitating bone fusion in an upper extremity of a patient.

BACKGROUND INFORMATION

In some instances bone fusion, or arthrodesis, of anatomy includingmultiple bone structures may be desirable, such as arthrodesis of theupper extremity bones of the wrist or hand. Wrist or carpus arthrodesisis an established surgical technique to join or fuse adjacent bones inthe wrist by rigidly positioning them at their articular surfaces. Bymaintaining this placement, sometimes in the presence of a bone graft,bone cell growth or other anatomical growth may be stimulated which maycause the bones to fuse together. Once the bones are fixed to oneanother, all motion that existed at the corresponding joint surfaces ofthe bones ceases, stability is achieved and any pain caused by theirritation of corresponding nerves is significantly reduced oreliminated. For example, in certain patients with post-traumaticarthritis, rheumatoid arthritis, osteoarthritis, carpal instability,complex or localized fractures or other injury, disease or destructiveor painful conditions involving the bones of the wrist, fusion ofparticular bones of the wrist can alleviate resulting pain, discomfortand instability. Unfortunately, effective fusion of the wrist whichbalances pain relief, joint stability and retention of some effectivemovement of the wrist is rarely achieved, no less consistently achieved.

Several surgical approaches have been developed to maximize alleviationof wrist pain and/or instability by arthrodesis. For example, totalwrist arthrodesis is very effective in relieving pain, but almost allwrist motion is lost. Since the articulation afforded to the hand by thewrist is important for mobility, strength and dexterity, total wristarthrodesis is often thought of as a last resort. As another example,limited or partial wrist arthrodesis is often desired in an effort topreserve motion of the wrist to the greatest degree possible. Partialwrist arthrodesis is fusion of a selected group of wrist bones.Variations of the procedure, such as triscaphe, radioscaphoid,radiolunate, scapholunate-capitate and four-corner fusion, attempt toalleviate pain by fusing particular articulations determined orsuspected of originating pain and/or instability. Partial wristarthrodesis is particularly advantageous in patients that desireintricate use of their hands because more residual motion of the wristcan be preserved.

Currently, in both total and partial wrist arthrodesis scenarios, it iscommon for plates, implants, wires, screws, staples and externalfixation devices to be used as the fusion medium. These devices are usedalone or in combination to attempt to achieve the desired level offusion.

The placement and orientation of the bones of the wrist at the time of awrist fusion is critical to obtaining a bony fusion, preserving maximalwrist motion in partial fusion, and preventing, for example, progressivearthritis of the wrist. One of the drawbacks encountered with prior artpartial fusion devices, methods and instrumentation is that they fail toprovide consistent and reproducible fusion, and therefore partialarthrodesis rarely results in full relief of pain. For example, whenplates, implants, screws and the like are used to achieve partial wristfusion, the exact placement of the particular plate, implant or screwsfrom surgeon to surgeon and patient to patient are rarely consistent. Assuch, the predictability of the exact clinical outcome of partial wristfusion with such prior art devices is low. As a result, there remainsmuch room for improvement in the art for effective fusion devices,methods and instrumentation that provide reproducible alignment,orientation and configuration of the fusion medium with respect totarget fixation bones in order to achieve predictable and consistentfusion of such target fixation bones.

Accordingly, it is an object of the present invention to overcome one ormore of the above-described drawbacks and/or disadvantages of the priorart. For example, in view of the deficiencies of current designs ofpartial wrist or hand fusion devices and methods, and similar fusiondevices and methods for other areas of the body where multiple bonestructures exist including, but not limited to, the foot, ankle andspine, and the lack of proper associated devices, instrumentation andmethods to achieve consistent post-operative results, it would bedesirable to develop devices, instrumentation and methods to allow asurgeon to achieve satisfactory long term, predictable clinical outcomesfor these types of fusion surgeries.

SUMMARY OF THE INVENTION

The present disclosure is directed to devices, instruments, clamps andmethods for fusing, or facilitating fusion, of bones of the upperextremity.

In accordance with one aspect of the present invention, a bone fusiondevice for use with bones of an upper extremity is disclosed. In someembodiments, the bone fusion device may include a fusion implantconfigured for implantation into a cavity spanning at least two adjacentbones, and at least two longitudinally extending bone fusion membersincluding a tip, a head and a shank extending longitudinally between thetip and the head.

In some such embodiments, the fusion implant may include a first endincluding an attachment mechanism configured to couple with aninstrument in a predefined first orientation, a second end substantiallyopposing the first end, and a body extending longitudinally between thefirst end and the second end. In some embodiments, the body may includea substantially smooth outer surface and define a longitudinal axis.

In some such embodiments, the body may further include at least twonon-threaded apertures extending laterally through the body from a firstside of the body to a second side of the body and at least twointernally threaded apertures including a first thread lead extendinglaterally through the body from a third side of the body to a fourthside of the body.

In some such embodiments, the at least two threaded apertures of thebody include a first threaded aperture proximate the first end, and asecond threaded aperture proximate the second end of the body. In someembodiments the second threaded aperture may be angled with respect tothe longitudinal axis of the body such that the second threaded aperturedefines an axis that angles away from the second end as it extends fromthe third side to the fourth side.

In some embodiments, the at least two bone fusion members include afirst externally threaded portion adjacent the tip including the firstthread lead and being otherwise configured to couple to the at least twothreaded apertures of the body of the fusion implant. In some suchembodiments, the at least two bone fusion members further includes asecond externally threaded portion adjacent the head including a secondthread lead that is less than the first thread lead and an externaltaper extending from the head to the tip. In some such embodiments, theat least two bone fusion members also include a non-threaded portionextending between the first and second externally threaded portions.

In some embodiments, the at least two non-threaded apertures of the bodydefine substantially parallel axes. In some embodiments, the fusionimplant is substantially cylindrical, and the first and second sides ofthe body are spaced about 90 degrees from the third and fourth sides ofthe body about the longitudinal axis.

In some embodiments, the body of the fusion implant includes a thirdinternally threaded aperture adjacent the second internally threadedaperture. In some such embodiments, the third internally threadedaperture extends laterally through the body and defines an axis that issubstantially parallel to the axis of the second internally threadedaperture. In some such embodiments, the fusion implant includes only twonon-threaded apertures and the first, second and third internallythreaded apertures. In some such embodiments, the first internallythreaded aperture is adjacent the first end, a first non-threadedaperture is positioned between the first internally threaded apertureand the second end, the third internally threaded aperture is positionedbetween the first non-threaded aperture and the second end, the secondinternally threaded aperture is positioned between the third internallythreaded aperture and the second end, and a second non-threaded apertureis positioned between the second internally threaded aperture and thesecond end.

In some such embodiments, the angle between the axis of the firstinternally threaded aperture and the longitudinal axis of the bodyadjacent the third side and first end of the body is within the range ofabout 95 degrees to about 80 degrees, and the angle between the axis ofthe second and third internally threaded apertures and the longitudinalaxis of the body adjacent the third side and first end of the body iswithin the range of about 92 degrees to about 106 degrees. In some suchembodiments, the first internally threaded aperture is angled withrespect to the longitudinal axis of the body such that it defines anaxis that angles away from the first end as it extends from the thirdside to the fourth side. In some such embodiments, a plane extendsbetween the axes of the internally threaded apertures and thelongitudinal axis of the body, and the axes of the non-threadedapertures are normal to the plane.

In some embodiments, the first threaded portion and the non-threadedportion of the at least two bone fusion members define a first outerdiameter, and the second threaded portion of the at least two bonefusion members defines a second outer diameter adjacent the head that isgreater than the first outer diameter.

In accordance with another aspect of the present invention, a surgicalinstrument for use in obtaining bone fusion in an upper extremity of apatient is disclosed. In some such embodiments, the instrument includesa fusion implant, a targeting member, at least one guide member and anoutrigger member.

In some such embodiments, the fusion implant includes a first end, asecond end and a body extending longitudinally therebetween defining afirst axis. In some such embodiments, the body includes at least oneaperture extending laterally therein defining a second axis.

In some such embodiments, the targeting member includes at least onearm, at least one bone fusion member aperture configured to receive abone anchor therethrough, and at least one clamp member configured tosecurely couple with a bone anchor member clamp.

In some such embodiments, the at least one guide member is coupled tothe at least one arm of the targeting member and includes an apertureextending through the at least one guide member defining a third axis.

In some such embodiments, the outrigger member is coupled to the atleast one arm of the targeting member and securely removably coupled tothe first end of the fusion implant in a first orientation of the fusionimplant. In some such embodiments, the outrigger member and the at leastone guide member are configured such that the second axis of the bonefusion member aperture of the fusion implant and the third axis of theaperture of the at least one guide member are substantially aligned inthe first orientation of the fusion implant.

In some such embodiments, the at least one arm of the targeting memberincludes at least a first arm extending from the targeting member to theoutrigger member, and a second arm extending from the targeting memberto the at least one guide member.

In some such embodiments, the first arm and the second arm areconfigured to space the outrigger member and the at least one guidemember from each other along the first axis of the fusion implant andalong the third axis of the aperture of the at least one guide member.In some other such embodiments the outrigger member and the first end ofthe fusion implant are configured to be securely removably coupled toone another in only the first orientation. In some other suchembodiments the outrigger member and the first end of the fusion implantare configured to provide a visual or tactile indication when they arecoupled to one another in an orientation different than the firstorientation. In some other such embodiments the instrument furtherincludes at least one bone anchor clamp configured to selectively coupleto the at least one clamp member and a bone anchor.

In accordance with another aspect of the present invention, a guideclamp for use in positioning a fusion implant in at least one bone toobtain a bone fusion in an upper extremity of a patient is disclosed. Insome such embodiments, the guide clamp includes a first arm member and asecond arm member.

In some such embodiments, the first arm member includes a longitudinallyextending guide member defining a first bone abutment surface and anaperture extending linearly therethrough defining a first axis.

In some such embodiments, the second arm member includes a bone abutmentmember spaced from the guide member and being in a first orientationwith respect to the first axis of the aperture of the guide member. Insome such embodiments, the bone abutment member includes a second boneabutment surface extending towards the first bone abutment surface inthe first orientation and a third bone abutment surface extending atleast to the first axis of the aperture of the guide member in the firstorientation

In some such embodiments, the first arm and the second arm are moveablycoupled to one another. In some such embodiments, the guide member andthe bone abutment member are configured such that the first orientationis maintained during movement of the first arm and guide member and thesecond arm and bone abutment member relative to the other.

In some embodiments, the first arm and second arm are hinged at a mediallocation of the arms, the guide member is rotatably coupled with thefirst arm, and the bone abutment member is rotatably coupled to thesecond arm. In some such embodiments, a positioning member is coupled tothe bone abutment member and the guide member in such a manner thatallows the abutment member and the guide member to rotate with theirrespective arms in response to movement of the first arm and second armabout the hinge to maintain the first orientation.

In accordance with another aspect of the present invention, a surgicalmethod for fusing bones is disclosed. In some embodiments, the surgicalmethod includes the step of drilling an implant aperture extendingthrough a first bone and at least partially through a second bone.

In some such embodiments, the surgical method further includes the stepof removably coupling a first end of a fusion implant including at leastone internally threaded bone fusion member aperture including a firstthread lead to a surgical targeting instrument in a first predefinedorientation dictated by the configuration of at least one of the firstend of the fusion implant and the surgical targeting instrument.

In some such embodiments, the surgical method further includes the stepof inserting the fusion implant within the implant aperture through thefirst bone and at least partially through the second bone such that atleast one of the least one internally threaded bone fusion memberaperture is positioned within the first bone.

In some such embodiments, the surgical method further includes the stepof positioning a first elongated aperture defining a first axis providedon the surgical targeting instrument proximate a third bone spacedelydisposed adjacent the first bone.

In some such embodiments, the surgical method further includes the stepof positioning a drill bit within the first elongated aperture providedon the surgical targeting instrument, and drilling along the first axisto form a bone fusion member aperture extending through the third boneand at least partially through the first bone to at least the at leastone internally threaded bone fusion member aperture.

In some such embodiments, the surgical method further includes the stepof rotationally inserting a first bone fusion member including a firstexternally threaded portion including the first thread lead adjacent atip of the member and a second externally threaded portion of a secondthread lead that is less than the first thread lead adjacent a head ofthe member into the bone fusion member aperture such that the firstexternally threaded portion is threadably engaged with the at least oneinternally threaded bone fusion member aperture, the second externallythreaded portion is engaged with the third bone, and the fusion implantand the first bone fusion member apply a compressive force to the jointbetween adjacent surfaces of the first bone and the second bone tofacilitate fusion therebetween.

In some such embodiments, the step of drilling an implant apertureincludes the step of applying a first bone abutment surface of a drillguide clamp to a first surface of the first bone and applying a secondbone abutment surface of the drill guide clamp to a second bone surfaceopposing the first bone surface of the second bone. In some suchembodiments, the step of drilling an implant aperture further includesthe step of positing a drill bit within a first elongated aperture ofthe drill guide clamp defining a second axis and drilling an implantaperture extending through the first bone and at least partially throughthe second bone from the first surface of the first bone toward thesecond bone abutment surface and second bone surface along the secondaxis.

In some such embodiments of the surgical method, the fusion implantincludes at least two internally threaded bone fusion member aperturesincluding the first thread lead and at least one of the at least twointernally threaded bone fusion member apertures is positioned withinthe second bone. In some such embodiments of the surgical method, thesurgical targeting instrument includes a second elongated aperturedefining a second axis.

In some such embodiments, the surgical method further includes the stepof positioning the second elongated aperture provided on the surgicaltargeting instrument proximate a fourth bone spacedely disposed adjacentthe second bone. In some such embodiments, the surgical method furtherincludes the step of positioning a drill bit within the second elongatedaperture provided on the surgical targeting instrument and drilling asecond bone fusion member aperture along the second axis extendingthrough at least the fourth bone and at least partially through thesecond bone to at least a second internally threaded bone fusion memberaperture of the fusion implant. In some such embodiments, the surgicalmethod further includes the step of rotationally inserting a second bonefusion member including a first externally threaded portion includingthe first thread lead adjacent a tip of the member and a secondexternally threaded portion of a second thread lead that is less thanthe first thread lead adjacent a head of the second member into thesecond bone fusion member aperture such that the first externallythreaded portion is threadably engaged with the second internallythreaded bone fusion member aperture, the second externally threadedportion is engaged with the fourth bone, and the space between thefourth bone and the second bone is substantially eliminated. Otherobjects, aspects and advantages of the fusion devices and methods of thepresent invention, and/or of the currently preferred embodimentsthereof, will become more readily apparent in view of the followingdetailed description of the currently preferred embodiments and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational perspective view of an exemplaryembodiment of a fusion implant of the present invention;

FIG. 2 is a rear elevational perspective view of the fusion implant ofFIG. 1;

FIG. 3 is a rear side view of the fusion implant of FIG. 1;

FIG. 4 is a front view of the fusion implant of FIG. 1;

FIG. 5 is a first side view of the fusion implant of FIG. 1;

FIG. 6 is a second side view of the fusion implant of FIG. 1;

FIG. 7 is a first cross-sectional side view of the fusion implant ofFIG. 1 taken along a plane defined by the longitudinal axis and the axesof the non-threaded apertures of the of the fusion implant;

FIG. 8 is a second cross-sectional side view of the fusion implant ofFIG. 1 taken along a plane defined by the longitudinal axis and the axesof the threaded-threaded apertures of the fusion implant;

FIG. 9 is a rear elevational perspective view of a first exemplaryembodiment of a fusion member of the present invention;

FIG. 10 is a front elevational perspective view of the fusion implant ofFIG. 9;

FIG. 11 is a side view of the fusion implant of FIG. 9;

FIG. 12 is a rear elevational perspective view of an exemplaryembodiment of a fusion device of the present invention;

FIG. 13 is a top view of the fusion device of FIG. 12;

FIG. 14 a front view of the fusion device of FIG. 12;

FIG. 15 is a rear elevational perspective view the fusion implant ofFIG. 12 implanted in exemplary bones of an upper extremity;

FIG. 16 is a top view the fusion implant of FIG. 12 implanted in theexemplary bones of an upper extremity of FIG. 15;

FIG. 17 is a front elevational perspective view of an exemplaryembodiment of a guide clamp of the present invention;

FIG. 18 is a front elevational perspective view of the guide clamp ofFIG. 17 applied to exemplary bones of an upper extremity;

FIG. 19 is a rear elevational perspective view an exemplary embodimentof a surgical instrument of the present invention;

FIG. 20 is a front elevational perspective view of the surgicalinstrument of FIG. 19;

FIG. 21 is a bottom view the surgical instrument of FIG. 19;

FIG. 22 is a longitudinal view of the surgical instrument of FIG. 19partially implanted in exemplary bones of a lower extremity and is use;

FIG. 23 is a bottom perspective view of the surgical instrument of FIG.19 partially implanted in exemplary bones of a lower extremity and isuse;

FIG. 24 is a side perspective view an exemplary embodiment of a clampthe present invention;

FIG. 25 is a front elevational perspective view of a first portion ofthe clamp of FIG. 24 applied to the surgical instrument of FIG. 19;

FIG. 26 is a front elevational perspective view of a first portion ofthe clamp of FIG. 24 applied to the surgical instrument of FIG. 19;

FIG. 27 is a front elevational perspective view of a first portion ofthe clamp of FIG. 24 applied to the surgical instrument of FIG. 19;

FIG. 28 is a front elevational perspective view of a first portion ofthe clamp of FIG. 24 applied to the surgical instrument of FIG. 19; and

FIG. 29 is a rear elevational perspective view of the clamp of FIG. 24applied to the surgical instrument of FIG. 19 partially implanted inexemplary bones of an upper extremity.

DETAILED DESCRIPTION

In this application, the words proximal, distal, anterior or palmar,posterior or dorsal, medial and lateral are defined by their standardusage for indicating a particular part or portion of a bone orprosthesis coupled thereto, or directional terms of reference, accordingto the relative disposition of the natural bone. For example, “proximal”means the portion of a bone or prosthesis nearest the torso, while“distal” indicates the portion of the bone or prosthesis farthest fromthe torso. As an example of directional usage of the terms, “anterior”refers to a direction towards the front side of the body, “posterior”refers to a direction towards the back side of the body, “medial” refersto a direction towards the midline of the body and “lateral” refers to adirection towards the sides or away from the midline of the body.Further, specifically in regards to the hand or wrist, the term “dorsal”refers to the top of the hand or wrist and the term “palmar” refers thebottom or palm of the hand or wrist. Similarly, positions or directionsmay be used herein with reference to anatomical structures or surfaces.For example, as the current devices, instrumentation and methods aredescribed herein with reference to use with the bones of the wrist, thebones of the wrist, hand and arm may be used to describe the surfaces,positions, directions or orientations of the devices, instrumentationand methods. Further, the devices, instrumentation and methods, and theaspects, components, features and the like thereof, disclosed herein aredescribed with respect to one side of the body for brevity purposes.However, as the human body is relatively symmetrical or mirrored about aline of symmetry (midline), it is hereby expressly contemplated that thedevices, instrumentation and methods, and the aspects, components,features and the like thereof, described and/or illustrated herein maybe changed, varied, modified, reconfigured or otherwise altered for useor association with another side of the body for a same or similarpurpose without departing from the spirit and scope of the invention.For example, the devices, instrumentation and methods, and the aspects,components, features and the like thereof, described herein with respectto the left wrist or hand may be mirrored so that they likewise functionwith the right wrist.

In FIGS. 1-8, a fusion implant embodying a first embodiment is indicatedgenerally by the reference numeral 10. As shown in FIGS. 1-8, the fusionimplant 10 may be a post-like member. The exemplary illustrated fusionimplant 10 is a substantially cylindrical member having a substantiallycircular cross-sectional geometry of constant thickness. In alternativeembodiments, the fusion implant 10 may define a non-cylindrical shape orany other geometrical shape and thicknesses (constant or varying).

As shown in the perspective views of FIGS. 1 and 2, the exemplaryillustrated fusion implant 10 includes an exemplary first end or tip 12and a substantially opposing exemplary second end 14. A body 16 of thefusion implant 10 extends between the first end 12 and the second end 14and defines an exemplary substantially smooth cylindrical shape definingthe longitudinal axis X-X. The body 16 includes apertures extendingtherethrough and a longitudinal axis of the device 10. In theillustrated embodiments, the longitudinal axis X-X of the body 16defines the longitudinal axis of the fusion implant 10. In alternativeembodiments, the longitudinal axis X-X of the body 16 differs from thelongitudinal axis of the fusion implant 10. In some embodiments, thefusion implant 10 and body 16 define a non-cylindrical shape andthickness (constant or varying). In some embodiments, the outer surfaceof the device includes external threads and/or at least a macro, microor nano texture or structure.

The apertures of the body 16 may include internally threaded andnon-threaded apertures extending through, or partially through, the body16 at different locations and angles or orientations. For example, someapertures may define an axis that passes through the longitudinal axisX-X, while other apertures may define an axis that is spaced from thelongitudinal axis X-X. The apertures may also define any shape or size,such as circular and non-circular apertures, and may extend linearly ornon-linearly through, or partially through, the body 16. The number ofthe internally threaded and non-threaded apertures may also vary, suchas a body 16 including at least one threaded aperture and not includingany non-threaded apertures, or a body 16 including at least one threadedaperture and at least one non-threaded aperture. In some embodiments,the body 16 may include at least two threaded apertures and at least onenon-threaded aperture.

In the illustrated embodiment, the exemplary body 16 includes threeexemplary threaded apertures 18A-C each defining axes and two exemplarynon-threaded apertures 20A, 20B each defining axes Y1-Y1, the axes ofthe threaded apertures 18A-C and non-threaded apertures 20A, 20Boriented substantially perpendicular to each another in at least oneplane. The exemplary threaded apertures 18A-C and non-threaded apertures20A, 20B extend substantially linearly entirely through the body 16 andpass substantially through the longitudinal axis X-X (i.e., theapertures pass through the entire thickness of the body 16). Theexemplary threaded apertures 18A-C and non-threaded apertures 20A, 20Bdefine substantially circular cross-sections, and thus are substantiallycylindrical in nature. The threaded apertures 18A-C may include internalthreads extending substantially along the entire length of the apertures18A-C, or the threading may extend to only a portion of the length ofthe apertures 18A-C. In the illustrated embodiment, the entire length orthickness of the threaded apertures 18A-C includes the internalthreading (see FIGS. 7 and 8). The inner surfaces of the non-threadedapertures 20A, 20B may define substantially straight and smoothsurfaces. In some embodiments, however, the inner surfaces of thenon-threaded apertures 20A, 20B do not define substantially straight andsmooth surfaces.

As shown best in FIGS. 3 and 4, the first end 12 of the fusion implant10 defines an exemplary tip profile with an asymmetrical shape withrespect to at least one plane passing through the longitudinal axis X-Xof the body 16. In the illustrated embodiment shown in FIGS. 1-8, thetip profile of the first end 12 is asymmetrical with respect to at leasta plane extending parallel to the longitudinal axis X-X andsubstantially normal to axes Y1-Y1 of the non-threaded apertures 20A,20B. As described in further detail below, the first end 12 isconfigured asymmetric with respect to at least one plane so that thefusion implant 10 properly mates or couples with an instrument in apredefined first orientation so that a specific, predefined alignmentbetween the fusion implant 10 and the instrument is consistentlyachieved (as well as the orientation of the fusion implant 10 withrespect to target fixation bones). For example, the first end 12 (and/orthe instrument) may be configured so that it can only mate or couplewith an instrument in the predefined first orientation. As anotherexample, the first end 12 may be configured such that it is capable ofmating or coupling with an instrument in multiple orientations,including the first orientation, but provides a visual, tactile or otherindication when the fusion implant 10 is mated or coupled in anorientation other than the first orientation. For example, the first end12 (and/or the instrument) may include visual or tactile markings,members, shapes or the like that provide at least one visual or tactileindication for facilitating mating or coupling the fusion implant 10 inthe first orientation.

As shown in FIGS. 3-6, the exemplary first end 12 of the illustratedfusion implant 10 includes four exemplary surfaces extending from theouter surface of the body 16 at acute angles toward the longitudinalaxis X-X. As best shown in FIGS. 3-6, the first end 12 includes anexemplary first planar tip surface 22 extending from a top portion ofthe outer surface of the body 16 and an exemplary second planar tipsurface 24 extending from an opposing bottom portion of the outersurface of the body 16. As illustrated in the front and rear side viewsof FIGS. 3 and 4, the first and second tip surfaces 22, 24 extend fromthe top and bottom outer surface portions of the body 16, respectively,linearly toward the longitudinal axis X-X of the body 16 at an angle θ1.As the outer surface of the exemplary body 16 is cylindrical, the firstand second tip surfaces 22, 24 also extend from their respective outersurface portions at the angle θ1. In the illustrated embodiment, thefirst and second tip surfaces 22, 24 are planar and extend from opposingsides of the body 16 at angle θ1 of about 45 degrees from thelongitudinal axis X-X of the device 10 and their respective outersurface portions, and therefore extend substantially perpendicular toeach other. As such, in the illustrated embodiment, the edges formed bythe outer surface of body 16 and the first and second tip surfaces 22,24 (i.e., the outer edges of the first and second tip surfaces 22, 24)are concaved towards the intermediate portion of the body 16.

The exemplary second tip surface 24 extends from a more intermediateportion of the body 16 as compared to the intermediate portion of thebody 16 from which the first tip surface 22 extends. However, the firstand second tip surfaces 22, 24 extend to the same longitudinal positionalong the longitudinal axis X-X. As such, the total length of the secondtip surface 24 measured from the most intermediate point to the outermost point is greater than the corresponding length of the first tipsurface 22 (whether measured along the longitudinal axis X-X or alongrespective planes defined by the surfaces 22, 24). As described above,and further described below, the difference in the total lengths of thefirst and second tip surfaces 22, 24 allows a user to accurately andconsistently couple the fusion implant 10 with an instrument in thepredefined first orientation.

As also illustrated in the side views of FIGS. 3 and 4, the illustratedfirst end 12 further includes exemplary third and fourth tip surfaces 26extending from the portions of the outer surface of the body 16 betweenthe first and second 22, 24 tip surfaces toward the longitudinal axisX-X of the body 16. The intermediate portions from which the exemplarythird and fourth tip surfaces 26 extend are less intermediate ascompared to the intermediate portions from which the first tip surface22 and second tip surface 24 extend. The exemplary third and fourth tipsurfaces 26 intersect, and extend between, the first and second tipsurfaces 22, 24. The third and fourth tip surfaces 26 are radiused toform blunt convex surfaces. In the illustrated embodiment, the third andfourth tip surfaces 26 are of identical shape, size, orientation andlongitudinal position along the axis X-X. Due to the configuration ofthe first and second tip surfaces 22, 24, as described above, the thirdand fourth tip surfaces 26 are not opposed from each other about thelongitudinal axis X-X of the body 16, but rather are skewed towards thetop portion of the body 16. As described below, this skewed oroff-center configuration ensures that the fusion implant will be coupledto an instrument in a pre-defined orientation. As such, the features ofthe fusion implant 10 can be designed with respect the pre-definedorientation.

The third and fourth radiused tip surfaces 26 intersect with respectiveexemplary planar first end tip surfaces 28. Each of the first and secondplanar tip surfaces 22, 24 also intersect with the exemplary planarfirst end tip surfaces 28. Each exemplary end tip surface 28 extendssubstantially perpendicular to the longitudinal axis X-X of the body 16,and defines the outer most surface of the fusion implant 10 at the firstend 12. Due to the configuration of the first and second tip surfaces22, 24 and the second and third tip surfaces 26, as described above, theend tip surfaces 28 are not opposed from each other about thelongitudinal axis X-X of the body 16, but rather are skewed towards thetop portion of the body 16. This skewed relationship or configuration ofthe first end 12 limits the orientations in which the first end 12 ofthe fusion member can be coupled to an instrument including a reversedor mirrored configuration of the first end 12, as described furtherbelow. For example, an instrument including a reversed or mirroredconfiguration of the first end 12 will be capable of properly orsecurely coupling to the first end 12 of the fusion implant 10 in onlytwo predefined orientations, one orientation being a “proper”orientation and the other being “improper.” Further, the off-centerorientation of the aspects of the first end 12 will provide a visual ortactile indication when the fusion implant 10 coupled to the instrumentin the “improper” orientation. In this way, the aspects of the “proper”orientation of the fusion implant 10 can be predetermined and designedfor a specific fusion application, since the first end ensures thefusion implant 10 will be orientated in the “proper” orientation. Asshown in FIG. 1, and described further below with respect to FIGS. 7 and8, the first end 12 further includes an aperture extending from the endtip surfaces 28 towards an intermediate portion of the body 16 about thelongitudinal axis X-X. The axially extending aperture thereby forms theinner edges of the end tip surfaces 28 and the first and second tipsurfaces 22, 24. As a result, in the illustrated embodiment, the inneredges of the end tip surfaces 28 and the first and second tip surfaces22, 24 are curved about the longitudinal axis X-X with the radius ofcurvature of the axially extending aperture. Also, the inner edges ofthe first and second tip surfaces 22, 24 formed by the axially extendingaperture are concaved towards the intermediate portion of the body 16.As the outer edges of the first and second tip surfaces 22, 24 are alsoconcaved, as discussed above, the profile of the first end 12 of thebody 16 is concaved towards the intermediate portion of the body 16 whenviewed from the top and bottom portions of the body 16.

The second end 14 of the fusion implant 10 and body 16 substantiallyopposes the first end 12, as shown in FIGS. 1-8. The second end mayinclude any configuration or shape. In the illustrated embodiment, asbest shown in FIGS. 2, 3 and 4, the second end 14 includes a planarsecond end tip surface 30 extending substantially normal to thelongitudinal axis X-X of the body 16 and parallel to the axes Y1-Y1 ofthe non-threaded apertures 20A, 20B. The second end tip surface 30defines the outer most surface of the fusion implant 10 at the secondend 14. In alternative embodiments, the second end tip surface 30 is notplanar, but radiused to form a blunt convex second end 14. In theillustrated embodiment, the second end 14 also includes acircumferential radiused edge 32 extending between the outer surface ofthe body 16 and the second end tip surface 30. In alternativeembodiments, the second end 14 does not include the radiused edge 32,and the second end tip surface 30, whatever its configuration or shape,extends to the outer surface of the body 16.

As illustrated in FIGS. 3 and 7, the total axial length L1 of the fusionimplant 10 along the longitudinal axis X-X can be measured from thefirst end surfaces 28 of the first end 12 to the second end surface 30of the second end 14. Similarly, the diameter D1 of the body 16 (andtherefore the diameter of the fusion implant 10) and can be measuredfrom opposing sides of outer surface of the body 16. The axial length L1and diameter D1 of the fusion implant 10 may vary and depend upon theparticular target fusion bones. For example, in the illustratedembodiment the fusion implant 10 is particularly well suited forimplantation into the hammate and capitate bones of the wrist for fusionof the triquetral and lunate bones, respectively, thereto, andpreferably defines an axial length L1 of about 0.95 inch and a diameterD1 of about 0.18 inch. In some embodiments, such as embodiments forimplantation into the bones of an upper extremity, the axial length L1of the fusion implant 10 may preferably range from about 0.8 inch toabout 1.2 inches, and more preferably from about 0.87 in to about 0.95inches. In some embodiments the diameter D1 of the body 16 and/or thefusion implant 10 may preferably range from about 0.15 inch to about 0.2inch, and more preferably range from about 0.15 inch to about 0.18 inch.In one embodiment, a fusion kit may include a plurality of fusionimplants 10 of differing axial lengths L1, such as a kit includingfusion implants 10 of axial lengths from about from 0.8 inch to about0.95 inches in about 0.08 inch increments. In some such embodiments, thekit further includes at least one fusion member configured to couple tothe fusion implants.

As shown in the front and rear side views of FIGS. 3 and 4, the threadedapertures 18A-C may be countersunk into the body 16 at the rear portionof the fusion implant 10 (FIG. 4) and flush with the outer surface ofthe body 16 at the front portion of the fusion implant 10 (FIG. 3). Thecountersink of the threaded apertures 18A-C may include respectiveconical or conical-like grooves 36 about each threaded aperture 18A-Cextending from the outer surface of the body 16 to the threadedapertures 18A-C. The grooves 36 may be of an oblong or othernon-circular shape because such grooves 36 may be formed in the body 16on an angle with respect to the outer surface of the body 16, and thusthe longitudinal axis X-X as well (i.e., the axis of the grooves 36 notbeing formed normal to the outer surface of the body 16). In theillustrated embodiment, the angle axis of the grooves 36 issubstantially aligned with the axis of the threaded apertures 18A-C. Thegrooves 36 may act to guide or reposition a fusion member, such as abone screw, that is not aligned and/or oriented with the position andorientation of the threaded apertures 18A-C into proper alignment and/ororientation therewith so the fusion member can engage the internalthreads. As such, grooves 36 that define axes substantially aligned withthe axes of the internally threaded apertures 18A-C may be particularlyadvantageous. The grooves 36 may or may not be considered part of theinternally threaded apertures 18A-C.

Similarly, as shown in the top and bottom side views of FIGS. 5 and 6,the non-threaded apertures 20A, 20B may also be countersunk into theouter surface body 16 at the top portion of the fusion implant 10 (FIG.5), but flush with the outer surface of the body 16 at the bottomportion of the fusion implant 10 (FIG. 6). The countersink of thenon-threaded apertures 20A, 20B may also include conical or conical-likegrooves 38 about each aperture 20A, 20B extending from the outer surfaceof the body 16 to the non-threaded apertures 18A-C. The axis of thegrooves 38 may be substantially aligned with the axes Y1-Y1 of thenon-threaded apertures 20A, 20B. The grooves 38 may act to guide orreposition a temporary or permanent bone anchor, such as a k-wire, thatis not completely aligned or oriented with the position and orientationof the non-threaded apertures 20A, 20B into alignment and orientationtherewith so the bone anchor passes therethrough. As such, grooves 38that define axes substantially aligned with the axes Y1-Y1 of thenon-threaded apertures 20A, 20B may be particularly advantageous. Thegrooves 38 may or may not be considered part of the non-threadedapertures 20A, 20B.

FIG. 7 shows a front sectional view of the fusion implant 10 taken alonga plane that is defined by the axes Y1-Y1 of the first and secondnon-threaded apertures 20A, 20B and the longitudinal axis X-X of thebody 16. As shown in FIG. 7, the first and second non-threaded apertures20A, 20B may extend linearly laterally through the body 16 such thattheir axes Y1-Y1 intersect with the longitudinal axis X-X of the body 16at an angle θ2 (i.e., the non-threaded apertures 20A, 20B extend throughthe entire thickness of the body 16). In the illustrated embodiment, thenon-threaded apertures 20A, 20B extend perpendicularly to thelongitudinal axis X-X of the body 16, and therefore the angle θ2 betweentheir axes Y1-Y1 and the longitudinal axis X-X shown is about 90degrees. As also shown in FIG. 7, the threaded apertures 20A-C may bealigned along a plane extending normally to the axes Y1-Y1 of thenon-threaded apertures and through the longitudinal axis X-X of the body16, and therefore positioned about 90 degrees about the body 16 from theaxes Y1-Y1 of the non-threaded apertures 20A, 20B. Stated differently,in the illustrated embodiment, the sides of the body 16 which thenon-threaded apertures 20A, 20B extend between are spaced about 90degrees about the longitudinal axis from the sides of the body 16 whichthe threaded apertures 20A-C extend between.

FIG. 8 shows a top sectional view of the fusion implant 10 taken along aplane normal to the axes Y1-Y1 of the non-threaded apertures 20A, 20Band through the longitudinal axis X-X of the body 16. As shown in FIG.7, the internally threaded apertures 18A-C may extend linearly laterallythrough the body 16 such that their respective axes Z1-Z1, Z2-Z2 andZ2-Z2 extend along a plane that passes through the longitudinal axis X-Xof the body 16 (i.e., the internally threaded apertures 18A-C extendthrough the entire thickness of the body 16). In such a configuration,the plane defined by the axes Z1-Z1, Z2-Z2 and Z2-Z2 of the internallythreaded apertures 18A-C, respectively, may be normal to the axes Y1-Y1of the non-threaded apertures 20A, 20B, as described above. Therefore,the sides of the body 16 which the axes Z1-Z1, Z2-Z2 and Z2-Z2 of thethreaded apertures 20A-C extend through are spaced about 90 degreesabout the longitudinal axis from the sides of the body 16 which the axesY1-Y1 of the non-threaded apertures 20A, 20B extend through. The axesZ1-Z1, Z2-Z2 and Z2-Z2 of the internally threaded apertures 18A-C mayangularly extend through the longitudinal axis X-X of the body 16, suchas extending at respective angles θ3, θ4, θ4 with respect to the rearsurface and the first end 12 of the body 16, as illustrated in FIG. 8.

As explained further below, the threaded apertures 18A-C may beconfigured to engage with fusion members, such as bone screws, to fuseadjacent bones to one another. As a result, the respective angles θ3, θ4and θ4 of the axes Z1-Z1, Z2-Z2 and Z2-Z2 of the threaded apertures18A-C may vary and depend upon the particular target fusion bones. Forexample, in the illustrated embodiment the fusion implant 10 isparticularly suited for insertion into the hammate and capitate bones ofthe wrist for fusion of the triquetral and lunate bones, respectively,thereto. As such, the axis Z1-Z1 of the first threaded aperture 18Aadjacent the first end 12 is set at an angle θ3 of about 87 degrees withthe longitudinal axis X-X of the body 16 with respect to the rear sideand the first end 12 of the body 16 (i.e., the axis Z1-Z1 of the firstthreaded aperture 18A extends away from the first end 12 as it extendsfrom the rear side to the front side of the body 16), and the axes Z2-Z2of the first and second threaded apertures 18B, 18C, respectively,adjacent the second end are set at an angle θ4 of about 99 degrees withthe longitudinal axis X-X of the body 16 with respect to the rear sideand the first end 12 of the body 16 (i.e., the axes Z1-Z1 of the firstand second threaded apertures 18B, 18C, respectively, extend away fromthe second end 14 as they extend from the rear side to the front side ofthe body 16).

In some embodiments, the axis Z1-Z1 of the first threaded aperture 18Aadjacent the first end 12 is set along the plane shown in FIG. 7 andpreferably at an angle θ3 with the longitudinal axis X1-X1 of the bodywith respect to the rear side and first end 12 of the body 16 within arange of about 80 degrees and about 95 degrees, and more preferablybetween a range of about 82 degrees and about 93 degrees. In someembodiments, the axes Z2-Z2 of the second and third threaded apertures18B and 18C, respectively, adjacent the second end 14 are set along theplane shown in FIG. 7 and preferably at an angle θ4 with thelongitudinal axis X1-X1 of the body 16 with respect to the rear side andthe tip 12 of the body 16 within a range of about 92 degrees and about106 degrees, and more preferably between a range of about 94 degrees andabout 104 degrees.

Therefore, in the illustrated embodiment, the axes Y1-Y1 of thenon-threaded apertures 20A, 20B are parallel to each other, and the axesZ2-Z2 of the first and second threaded apertures 18B and 18C areparallel to each. Further, the axis Z1-Z1 of the first threaded aperture18A is planar with the axes Z2-Z2 of the first and second threadedapertures 18B and 18C, and such plane is normal axes Y1-Y1 of thenon-threaded apertures 20A, 20B. Stated differently, a plane extendingbetween the axes Y1-Y1 of the non-threaded apertures 20A, 20B (plane ofFIG. 7) is perpendicular with respect to a plane extending through theaxes Z1-Z1, Z2-Z2, Z2-Z2 of the threaded apertures 18A-C (plane of FIG.8).

The internal or female threads of the threaded apertures 18A-C may beconfigured to interact with a fusion member, such as a bone screw, tocouple the fusion member to the device 10. Thus, if the fusion implant10 is implanted in one or more bones, and multiple fusion members areimplanted into adjacent bones and into engagement with the threadedapertures 18A-C, the fusion implant 10 and threaded apertures 18A-C actin concert to fuse the adjacent bones to one another. Thecharacteristics of the threading of the threaded apertures 18A-C, suchas thread lead, may thus be dependent upon, or related to, thecharacteristics of the threading of fusion members. In some embodiments,the internal threading of the threaded apertures 18A-C is a two-start,right handed threading, when viewed from the grooves 36 or rear side ofthe body 16, that includes an about 0.08 inch nominal diameter, a threadlead of about 0.03 inches, and a thread pitch of about 0.015 inches. Inthe illustrated embodiment, the internal threading of the threadedapertures 18A-C is a two-start, right handed threading (when viewed fromthe grooves 36 or rear side of the body 16) that includes an about 2millimeter nominal diameter, a thread lead of about 0.8 millimeters, anda thread pitch of about 0.4 millimeters. In alternative embodiments,locking mechanisms other than internal threads may be used. For example,in some embodiments the apertures 18A-C do not include internal threads,rather they are configured to mate with fusion members throughalternative locking mechanisms, such as key and slot agreement, detentmechanism, friction taper and interference fit. In addition, the use ofdifferent materials (metals or biologics) between the fusion implant 10and fusion members could facilitate the locking of the fusion devicesand resultant securement.

The non-threaded apertures 20A, 20B may be configured to interact with atemporary or permanent anchor member to temporarily or permanentlycouple, at least in part, the fusion implant 10 to bones and/or thefusion implant 10 or target fusion bones to an instrument. For example,in the illustrated embodiment, the non-threaded apertures 20A, 20B areshaped and sized to accept a k-wire therethrough (a temporary boneanchor). In the illustrated embodiment, the diameter of the non-threadedapertures 20A, 20B is sized to receive an industry standard 1.6millimeter k-wire therethrough, and therefore the diameter of thenon-threaded apertures 20A, 20B is at least about 0.63 inches.

As shown in FIG. 8, the non-threaded apertures 20A, 20B and threadedapertures 18A-C can be spaced along the longitudinal axis X-X of thebody 16 (and thus along the fusion implant 10 itself) between the firstend 12 and the second end 14. The number and relative positioning of thenon-threaded apertures 20A, 20B and threaded apertures 18A-C may varyand depend upon the particular bone structures which are desired to befused. For example, in the illustrated embodiment the fusion implant 10is particularly well suited for insertion into the hammate and capitatebones of the wrist for fusion of the triquetral and lunate bones,respectively, thereto, with the use of bone screws. As shown in FIG. 8,for such a use, the fusion implant 10 may include three internallythreaded apertures 18A-C and two non-threaded apertures 20A, 20B. Thenon-threaded apertures 20A, 20B may be arranged such that a firstnon-threaded aperture 20A is located in an intermediate portion of thebody 16 and a second non-threaded aperture 20B is located adjacent thesecond end 14 of the body 16. In the illustrated embodiment, the axisY1-Y1 of the intermediate first non-threaded aperture 20A is axiallyspaced a distance L4 of about 0.45 inches from the outer most surface ofthe first end (e.g., first end tip surfaces 28), the axis Y1-Y1 of thesecond non-threaded aperture 20B adjacent the second end 14 is axiallyspaced from the outer most surface of the second end 14 (e.g., tipsurface 30) a distance L2 of about 0.06 inches, and the axial distanceL3 between the axis Y1-Y1 of the first non-threaded aperture 20A and theaxis Y1-Y1 of the second non-threaded aperture 20B is about 0.43 inches.

As also shown in FIG. 8, for such a use second and third internallythreaded apertures 18B, 18C may be paired together and positionedbetween the first and second non-threaded apertures 20A, 20B, such thatthe third threaded aperture 18C is adjacent the second non-threadedaperture 20B that is adjacent the first end 14, and the second threadedaperture 18B is adjacent the intermediate first non-threaded aperture20A. In the illustrated embodiment, the axes Z2-Z2 of the pair ofparallel second and third threaded apertures 18B and 18C are axiallyspaced from one another a distance L5 of about 0.18 inches, the axialdistance L6 between the axis Z2-Z2 of the third threaded aperture 18C atthe point where it intersects the longitudinal axis X-X of the body 16and the axis Y1-Y1 of the second non-threaded aperture 20B is about 0.11inches, and the axial distance L7 between the axis Z2-Z2 of the secondthreaded aperture 18B at the point where it intersects the longitudinalaxis X-X of the body 16 and the axis Y1-Y1 of the first non-threadedaperture 20A is about 0.145 inches.

As also shown in FIG. 8, the first threaded aperture 18A may be positedbetween the intermediate first non-threaded aperture 20A and the firstend 12. In the illustrated embodiment, the axial distance L8 between theaxis Z1-Z1 of the first threaded aperture 18A at the point where itintersects the longitudinal axis X-X of the body 16 and the axis Y1-Y1of the intermediate first non-threaded aperture 20A is about 0.13inches. Also, in the illustrated embodiment the axial distance L9between the axis Z1-Z1 of the first threaded aperture 18A at the pointwhere it intersects the longitudinal axis X-X of the body 16 and theouter most point of the first end 12 (e.g., first end tip surfaces 28)is about 0.32 inches. Still further, in the illustrated embodiment theaxial distance L10 between the axis Z1-Z1 of the first threaded aperture18A and the axis Z2-Z2 of the second threaded aperture 18B at the pointwhere they intersect the longitudinal axis X-X of the body 16 is about0.28 inches, and the axial distance L11 between the axis Z1-Z1 of thefirst threaded aperture 18A and the axis Z2-Z2 of the third threadedaperture 18C at the point where they intersect the longitudinal axis X-Xof the body 16 is about 0.46 inches.

As shown best in the cross-sectional views of FIGS. 7 and 8, the firstend 12 includes a substantially cylindrical aperture 40 extending intothe body 16 about longitudinal axis X-X of the body 16. The cylindricalaperture 40 may include an internally threaded portion 42 positioned atan intermediate portion of the cylindrical aperture 40. The internallythreaded portion 42 may define a diameter that is less than the diameterof the outer non-threaded portion of the cylindrical aperture 40 that isadjacent the first end 12. The cylindrical aperture 40 may be used tocouple the first end 12 of the fusion implant 10 to an instrument in apredefined orientation of the fusion implant 10.

As discussed above, the fusion implant 10 may be paired with fusionmembers, such as bone screws, to form a fusion device capable of fusingadjacent bones. An exemplary fusion member is shown in FIGS. 9-11.Exemplary fusion member 50 of FIGS. 9-11 is an externally threaded bonescrew. Exemplary bone screw 50 may preferably be configured to couple tothe threaded apertures 18A-C to form a fusion device (as shown in FIGS.13-19), such as a bone fusion device. For example, the fusion implant 10may be implanted into first and second adjacent bones, and a bone screw50 may be implanted through each of third and fourth bones adjacent thefirst and second bones, respectively, and engaged with one of thethreaded apertures 18A-C of the fusion implant 10 to fuse the first andsecond bones to the third and fourth bones, respectively.

In some embodiments, exemplary bone screw 50 is a self-tapping screwconfigured to cut threads and advance into bone through rotation of thescrew 50, as shown in FIGS. 9-11. As shown in the illustrated bone screw50, the bone screw 50 may include a tip 52 defining a first end of thebone screw 50 and a head 54 defining an opposing second end of the bonescrew 50, and a longitudinal axis X2-X2 extending between the tip 52 andthe head 54. The tip 52 may define a substantially flat circularsurface, and the portion of the bone screw 50 adjacent the tip maynarrow or taper to provide a tapered profile, as shown best in FIG. 9.In alternative embodiments, the tip 52 is radiused, curved or otherwiseconfigured to provide a smooth tip surface void of sharp edges (otherthan the threads, for example). The head 54 may also define asubstantially flat surface, but may include an aperture configured toengage a tool to apply rotational force to the bone screw 50 via theaperture. For example, in the illustrated embodiment show best in FIG.10, the head 54 includes a flat surface with a hexagonal or hexalobeshaped aperture extending therein.

The bone screw 50 may define a cylindrical-like shank or body extendingbetween the tip 52 and the head 54 and be substantially symmetricallydisposed about the longitudinal axis X2-X2. The total axial length ofthe bone screw 50 measured from the tip 52 to the head 54, and thelargest diameter of the screw 50, may vary depending upon the particulartarget fusion bones. As shown in FIG. 11, the illustrated bone screw 50is particularly well suited for implantation into the lunate and hammatebones, and the triquetral and capitate bones, of the wrist andpreferably defines a total axial length within the range of about 0.7inch to about 1.2 inches, such as axial lengths L12 of about 0.71 inch,about 0.79 inch, about 0.87 inch, about 0.94 inch, about 1.02 inches,about 1.1 inches and about 1.18 inches. In some such embodiments thetotal axial length L12 of the bone screw more preferably ranges fromabout 18 millimeters to about 30 millimeters. In the illustratedembodiment, the total axial length L12 of the bone screw 50 is about0.94 inch. In one embodiment, a fusion kit may include a plurality ofbone screws 50 of differing axial lengths L12, such as a kit includingbone screws 50 of axial lengths 12 from about from 0.7 inch to about 1.2inches in about 0.8 inch increments. In some such embodiments the kitmay further include at least one fusion implant 10 configured to coupleto the bone screws 50.

As shown in FIGS. 9-11, the shank or body of the fusion member 50 mayinclude a first threaded portion 56 adjacent the tip 52, a secondthreaded portion 60 adjacent the head 54, and an intermediatenon-threaded portion 58 axially positioned between the first threadedportion 56 and the second threaded portion 60. The first threadedportion 56 adjacent the tip 52 may include male or exterior helicalthreading, and such exterior threading may include a double start ordouble lead thread and a self-tapping feature. As illustrated best inFIG. 9, the self-tapping feature may include at least one flute orrelief 62 disposed into the periphery of the shank of the first threadedportion 56, such as three reliefs 62 symmetrically disposed about theaxis X2-X2 of the fusion member 50. In such an embodiment includingmultiple reliefs 62, such, flutes or reliefs 62 interrupt the threadedportion 60 and the threading thereon to form interrupted threadedportions 61 therebetween.

The at least one relief 62 may axially extent partially along the axiallength L13 of the first threaded portion 56 from the tip 52. Forexample, in the illustrated embodiment shown in FIG. 11, the axiallength L13 of the first threaded portion 56 of the fusion member 50 isabout 0.3 inch, and the axial length L14 of each of the three reliefs orflutes 62 is less than about 0.3 inch. In some embodiments, the axiallength L13 of the first threaded portion 56 is preferably greater thanabout 10 percent, and less than about 90 percent, of the total axiallength L12 of the fusion member 50, and more preferably greater thanabout 25 percent, and less than about 75 percent, of the total axiallength L12 of the fusion member 50. Further, in some embodiments, theaxial length L14 of each relief 62 is preferably greater than about 10percent, and less than about 90 percent, of the axial length L13 of thefirst threaded portion 56, and more preferably greater than about 25percent, and less than about 75 percent, of the axial length L13 of thefirst threaded portion 56. It is noted however, that the axial lengthL13 of the first threaded portion 56 and the axial length L14 of eachrelief 62 may depend upon, or at least be related to, the axial lengthsof the other portions of the fusion member 50. Further, the axial lengthL13 of the first threaded portion 56, as well as the axial length ofeach relief 62, may depend upon, or at least be related to, a particularclinical need, injury, patient size and/or fusion implant, and thereforefusion members 50 including axial lengths L13 and L14 outside the rangespresented above may be desirable.

The intermediate portion of the at least one flute or relief 62 may beradiused to provide a smooth transition between the at least one relief62 and the adjacent portion of the shank, such as a relief-free portionof the first threaded portion 56 in embodiments where the axial lengthof the at least one relief 62 is less than the axial length of the firstthreaded portion 56. For example, as shown in the illustrated embodimentin FIGS. 9-11, the trailing surface 64 of each relief 62, with respectto the direction of rotation R, may include a radiused portion 66 thattransitions the junction of each relief 62 and the intermediate portionof the first threaded portion 56 that is void of the at least one relief62. In one embodiment, the radius of the radiused portion 66 is about0.08 inch.

The at least one relief 62 may also include a leading surface 68 thatdefines a leading edge extending between the leading surface 68 and theexterior of the adjacent interrupted portion 61, with respect to thedirection of rotation R. In such an embodiment, the leading surface 68may be angled with respect to the longitudinal axis X2-X2 such that anacute angle is formed between the leading surface 68 and the interruptedexterior threaded portion 61. The acute angle formed between thesurfaces may facilitate the cutting of threads in bone via the leadingedge when the screw 50 is applied to a bone surface and rotated in thedirection of rotation R. During such a self-tapping process, the atleast one flute or relief 62 may provide a cavity or channel in whichbone chips, dust or other debris resulting from the self-tapping processcan collect and thereby prevented from interfering with the self-tappingprocess.

As described above, the exterior threading of the first threaded portion56 is provided helically along the first portion 56 with respect to adirection of rotation R about the axis X2-X2. In the illustratedembodiment, the exterior threading of the first threaded portion 56 isright-hand thread such that the threading causes the fusion member 50 toadvance in a direction along the axis X2-X2 from the head 54 to the tip52 upon clockwise rotation of the member 50 about the axis X2-X2. In analternative embodiment, the exterior threading of the first threadedportion 56 is a left-hand thread. It is noted, however, that theparticular handedness of the exterior threading of the first threadedportion 56 of the fusion member 50 is dependent only with respect to thehandedness of the internal threading of the internally threadedapertures 18A-C of the fusion implant 10, as the fusion member 50 andfusion implant 10 are preferably configured to threadably coupled to oneanother via the internally threaded apertures 18A-C.

The exterior or male threading of the first threaded portion 56 may be asingle, double or other multiple start threading and may include aconstant for varying diameter, pitch and lead. For example, in oneembodiment the threading of the first threaded portion 56 is a doublestart threading that includes an about 0.08 inch diameter, a thread leadof about 0.03 inches, and a thread pitch of about 0.015 inches. In theillustrated embodiment, the threading of the first threaded portion 56is a two-start, right handed threading (when viewed from the head 54)that includes an about 2 millimeter nominal diameter, a thread lead ofabout 0.8 millimeter, and a thread pitch of about 0.4 millimeter. Insome embodiments, the threading of the first threaded portion 56 is amachine type threading. It is noted, however, that the type, diameter,pitch, length, number of starts, thread profile and any othercharacteristic of the threading of the first threaded portion 56 may bedependent upon, or at least related to, the respective characteristic ofthe threading of the internally threaded apertures 18A-C of the fusionimplant 10. As such, the exterior threading of the first threadedportion 56 of the bone screw 50 and the internal threading of thethreaded apertures 18A-C of the fusion implant 10 of the illustratedembodiment are configured to mate with one another, and therefore bothdefine two-start, right handed threading (when viewed from the head 54of the fusion member 50 and from the rear side or grooves 36 of theimplant 10) that includes about a 2 millimeter nominal diameter, athread lead of about 0.8 millimeters, and a thread pitch of about 0.4millimeters. In some such embodiments, the diameter is about 0.076 inch.

The portion of the bone screw 50 that is positioned adjacent the firstthreaded portion 56 may be a non-threaded portion 58, as shown in FIGS.9-11. The non-threaded portion 58 may define a relatively smooth,uninterrupted outer surface of a diameter D2. In some embodiments, thenon-threaded portion 58 may include some type of macro, micro or nanotexture, structure or coating. As shown in FIG. 11, the non-threadedportion 58 may extend along the longitudinal axis X2-X2 of the bonescrew for an axial length L16. In some embodiments, the axial length L16of the non-threaded portion 58 is greater than the axial length of thefirst threaded portion 56. In some embodiments, the axial length L13 ofthe non-threaded portion 58 is preferably greater than about 10 percent,and less than about 90 percent, of the total axial length L12 of thefusion member 50, and more preferably greater than about 25 percent, andless than about 75 percent, of the total axial length L12 of the fusionmember 50. It is noted however, that the axial length L16 of thenon-threaded portion 58 may depend upon, or at least be related to, theaxial lengths of the other portions of the fusion member 50. Further,the axial length L16 of the non-threaded portion 58 may depend upon, orat least be related to, a particular clinical need, injury, patient sizeand/or fusion implant, and therefore fusion members 50 including axiallengths L16 outside the ranges presented above may be desirable. Asanother example, in some exemplary embodiments the total axial lengthL12 of the bone screw ranges from about 18 millimeters to about 30millimeters in about 2 millimeter increments, and such 2 millimeteraxial length increments are provided by 2 millimeter differences in theaxial length of the non-threaded portion 58 (i.e., the length L13 of thefirst threaded portion 56 and the length L17 of the second threadedportion 60 remain the same).

As shown in FIGS. 9-11, the fusion member 50 may include a secondthreaded portion 60 adjacent the head 54 and non-threaded portion 58.The second threaded portion 60 may include male or exterior helicalthreads. The exterior or male threading of the second threaded portion60 may be a single, double or other multiple start threading, and mayinclude constant or varying diameter, pitch and lead. In someembodiments, the threading is a cancellous type threading (e.g., acoarse thread threaded to only the first third of the length of thefusion member 50).

In some embodiments, the thread lead is dependent upon, or related to,the thread lead of the exterior threading of the first threaded portionand the internal threading of the internally threaded apertures 18A-C ofthe fusion implant 10. In some such embodiments, the thread lead of thethreading of the second threaded portion 60 is less than the thread leadof the threading of the first threaded portion 56 and the internallythreaded apertures 18A-C. Stated differently, in some embodiments thethread lead of the threading of the first threaded portion 56 (i.e., thethreading adjacent the tip 52) and the internally threaded apertures18A-C may be greater than the thread lead of the threading of the secondthreaded portion 60 (i.e., the threading adjacent the head 54). In somesuch embodiments where the threading of the second threaded portion 60is a single start thread, the thread lead and pitch are less than thethread lead of the first threaded portion 56 and the internally threadedapertures 18A-C (because the thread lead and pitch are the same). Forexample, in one embodiment the threading of the second threaded portion60 is a single start threading that includes an about 0.027 inch threadlead and thread pitch, and the threading of the internally threadedapertures 18A-C and second threaded portion 56 include an about 0.03inch thread lead. In the illustrated embodiment, the threading of thesecond threaded portion 60 is a single-start, right handed threading(when viewed from the head 54) that includes an about 0.7 millimeterthread lead and pitch.

In some embodiments, the axial length L17 of the second threaded portion60 is less than the axial lengths L16, L13 of the non-threaded portion58 and the first threaded portion 56. In some embodiments, the axiallength L17 of the second threaded portion 60 is preferably greater thanabout 10 percent, and less than about 90 percent, of the total axiallength L12 of the fusion member 50, and more preferably greater thanabout 25 percent, and less than about 75 percent, of the total axiallength L12 of the fusion member 50. It is noted however, that the axiallength L17 of the second threaded portion 60 may depend upon, or atleast be related to, the axial lengths of the other portions of thefusion member 50. Further, the axial length L17 of the second threadedportion 60 may depend upon, or at least be related to, a particularclinical need, injury, patient size and/or fusion implant, and thereforefusion members 50 including axial lengths L17 outside the rangespresented above may be desirable. In the illustrated embodiment shown inFIGS. 9-11, the axial length L17 of the second threaded portion 60 isabout 0.2 inch.

The second threaded portion 60 may include a compression wedge ortapered profile extending from the head 54 to the non-threaded portion58, as shown in FIGS. 9-11. In some such embodiments, the majordiameters formed by the outer edges of the threads and the minordiameters formed by the gullets between the threads both taper (i.e.,tapered threading). In some other such embodiments, only one of themajor and minor diameters of the threading of the threaded portion 60tapers. In the illustrated embodiment, the major diameter of the threadstapers from the head 54 to the non-threaded portion 58, but the minordiameter defined by the gullets remains constant along the axial lengthL17 of the second threaded portion 60. The tapering of the majordiameter of the threads of the second threaded portion 58 may be formedby threads of differing thread profile with differing thread depth orpercentage of thread. For example, as shown in the illustratedembodiment, the threads of the second threaded portion 60 may bemachined to define progressively shorter thread depths and wider crestswhich are angled with respect to the longitudinal axis X2-X2 of thefusion member 50 from the head 54 to the non-threaded portion 58 to formthe tapered profile. In the illustrated embodiment, the major diameterof the threads of the second threaded portion 60 taper at an angle ofabout 7 degrees with respect to the longitudinal axis X2-X2 of thefusion member 50. In some embodiments, the taper of the major diameterof the threads of the second threaded portion 60 preferably ranges froma minimum taper angle that will effectively provide a “wedge”characteristic that prevents the fusion member 50 from being pulledthrough the particular bone that the second threaded portion 60 isimplanted in, to a maximum taper angle that will effectively allow thefusion member 50 to be implanted at least partially through a fusionbone 50 and rotate therein to, eventually, achieve fusion.

As shown best in FIGS. 10 and 11, the second threaded portion 60 isadjacent the head 54 of the fusion member 50. The head 54 may include alateral surface defining the end or most axial surface of the fusionmember 50 opposing the tip 52. In the illustrated embodiment, the head54 includes a planar surface that is normal to the longitudinal axisX2-X2 of the fusion member 50. As discussed above, the head 54 mayinclude an aperture or other mechanism capable of applying torque to thefusion member 50. The threading of the second threaded portion 60 maycontinue to the head surface 54 such that the major diameter of thethreads decreases at is approaches the head 54. In an alternativeembodiment, the head 50 may not be a lateral surface, but may be amember defined along the longitudinal axis X2-X2 and positioned adjacentthe second threaded portion 50.

Fusion member 50 embodiments including such a greater thread lead of thethreading adjacent the tip 52 (e.g., the first threaded portion 56) andthe threading of the internally threaded apertures 18A-C of the fusionimplant 10 as compared to threading adjacent the head 54 (e.g., thesecond threaded portion 60), may be advantageous for facilitating bonefusion because such a thread arrangement may act to pull adjacent bonesinto contact with each other and, depending upon the level of rotationof the fusion member, apply a compressive force or load to the jointbetween the bone surfaces contacting each other. For example, when afusion implant 10 is implanted into a first bone, such a fusion member50 can be rotatably advanced into an adjacent but spaced second bone tosuch a degree that the second threaded portion 60 is in engagement withthe first bone and the first threaded portion 56 has partially orprimarily passed through the second bone and into the first bone andengagement with an internally threaded aperture 18A-C of the fusionimplant 10 implanted therein. In such a position, further clockwiserotation of the fusion member 50 results in the fusion member 50traveling farther along its longitudinal axis X2-X2 per unit ofrevolution through the first bone and implant 10 than in the second bone(because the differences of thread lead of the first threaded portion 56and second threaded portion 60). As a result, rotation of the fusionmember 50 acts to pull the second bone (via the threads of the secondthreaded portion 60) towards the first bone to reduce the space betweenadjacent surfaces of the bones.

After the space between the first and second bones is eliminated and theadjacent surfaces meet (i.e., first and second bones in abutment),further rotation of the fusion member 50 will apply compressive forcesto the joint between the adjacent surfaces because the second threadedportion 60 engages the inner surfaces of second bone and thereby resistsbeing pulled through the second bone as the first threaded 56 portionadvances in the first bone and fusion implant 10. The wedge or tapershape of the second threaded portion 60 may facilitate such engagementwith the interior of the second bone that prevents the second threadedportion 60 from being pulled therethrough, and application of thecompressive force. As a result, the thread leads and the relativelengths of the first and second bones, the first threaded portion 56,the second threaded portion 60 and the non-threaded portion 58 must beproperly proportioned to utilize the fusion member 50 and implant 10 toprovide a secure construct that facilitates fusion of the first andsecond bones. For example, the above mentioned aspects must be properlyproportioned or related such that the first threaded portion 56 does notpass through the implant 10 before the space between the target fusionbones is eliminated, the space between the target fusion bones is noteliminated before the fusion member 50 engages the fusion implant 10,the first and second threaded portions 56, 60 do not substantiallyengage the same bone at the same time (the non-threaded portion 58 spansthe joint), and the fusion member 50 does not strip out or fail toengage the first bone, second bone or fusion implant 10.

As shown in FIGS. 12-13, an exemplary fusion device 70 may include afusion implant and at least two fusion members, such as the illustratedexemplary fusion implant 10 and illustrated exemplary fusion member 50described above. A first fusion member 50A may be threadably engagedwith the implant 10 via the first internally threaded aperture 18Aadjacent the first end or tip 12 and a second fusion member 50 may bethreadably engaged with the implant 10 via the second internallythreaded aperture 18B intermediately positioned in the body 16. Thethird internally threaded aperture 18C adjacent the second end 14 may ormay not include a third fusion member 50. As illustrated best in FIGS.11 and 13, in such an arrangement or construct the axes X2-X2 of thefirst and second fusion members 50A, 50B will substantially align withthe axes Z1-Z1, Z2-Z2 of the first and second internally threadedapertures 18A, 18B, respectively. Therefore, in such a construct thedescription presented above with respect to the illustrated anddescribed positioning, arrangements, orientations and the like of thefirst and second internally threaded apertures 18A, 18B and/or theirrespective axes Z1-Z1, Z2-Z2 equally applies to the first and secondfusion members 50A, 50B and is not repeated herein with respect to thefusion members 50A, 50B for brevity purposes. Similarly, the descriptionpresented above with respect to the positioning, arrangements,orientations and the like of the first and second non-threaded apertures20A, 20B and/or their axes Y1-Y1 with respect to each other and thefirst and second internally threaded apertures 18A, 18B equally appliesto the first and second fusion members 50A, 50B and is not repeatedherein with respect to the fusion members 50A, 50B for brevity purposes.

As shown in FIG. 13, the first and second fusion members 50A, 50B may bepositioned within the first and second internally threaded apertures18A, 18B (e.g., via rotation) such that the first threaded portions 56thereof partially pass through the apertures 18A, 18B and body 16 of theimplant 10. In such an arrangement, the first fusion member 50A may beengaged with first aperture 18A to a degree that is more, less or thesame as the degree to which the second fusion member 50B is engaged withthe second aperture 18B. Further, the first threaded portions 56 may bepositioned on both the front and rear sides of the body 16, or may bepositioned only on the rear side of the body 16 (in addition to withinthe internally threaded apertures 18A, 18B). In some other embodiments,the first threaded portions 56 may be positioned only on the front sideof the body (in addition to within the internally threaded apertures18A, 18B). In the illustrated embodiment, the first threaded portion 56of the first and second fusion members 50A, 50B partially pass throughthe first and second internally threaded apertures 18A, 18B to the sameextent as each other and to such an extent that a portion of the flutesor reliefs 62 are positioned on the front side of the body 16 and theremaining portions of the first and second fusion members 50A, 50B arepositioned on the rear side of the body (besides the portions that arepositioned within the first and second apertures 18A, 18B).

Exemplary fusion device 70 may be well suited for providing orfacilitating fusion of adjacent bones, as shown in FIGS. 15 and 16. Thefusion implant 10 may be particularly well suited for implantation intofirst B1 and second B2 adjacent bones, the first fusion member 50A maybe particularly well suited for implantation into a third bone B3adjacent the first bone B1 and into the first bone B1 (and into thefirst internally threaded aperture 18A), and the second fusion member50B may be particularly well suited for implantation into a fourth boneB4 adjacent both the second bone B2 and the third bone B3 and into thesecond bone B2 (and into the second internally threaded aperture 18B).In such a construct, the fusion device 70 provides or facilitates fusionof at least the first bone B1 and third bone B3 (via the first fusionmember 50A and implant 10), and the second bone B2 and fourth bone B4 B3(via the second fusion member 50B and implant 10). In the illustratedembodiment, the first bone B1 is the capitate bone, the second bone B2is the hammate bone, the third bone B3 is the lunate bone and the fourthbone B4 is the triquetral bone. In the illustrated embodiment, thedevice 10 provides fusion of the lunate and capitate bones, and thetriquetral and hammate bones, and because the natural joint between thehammate and capitate bones is relatively stable, the device 70effectively provides fusion of the hammate, capitate, lunate andtriquetral bones.

As shown in the rear or proximal elevational (dorsal) perspective viewof FIG. 15 and the top or dorsal view of FIG. 16, the fusion implant 10can be implanted in an orientation such that the front or first side ofthe body 16 (the side that includes the grooves 36A-C and the axesZ1-Z1, Z2-Z2 of the internally threaded apertures 18A-C) generally facesproximally, the rear or second side of the body 16 (the side thatopposes the front or first side) generally faces distally, the top orthird side of the body 16 (the side that includes the grooves 38A, 38Band axes Y1-Y1 of the non-threaded apertures 20A, 20B) generally facesdorsally, and the bottom or fourth side of the body 16 (the side thatopposes the top or third side) generally faces in the palmar direction.As such, the longitudinal axis X-X of the body 16 generally extends in amedial-lateral direction from the second end 14 to the first end 12, theaxes Z1-Z1, Z2-Z2 of the internally threaded apertures 18A-C and theaxes X2-X2 of the fusion members 50A, 50B generally extend in aproximal-distal direction from the head 54 to the tip 52, and the axesY1-Y1 of the non-threaded apertures 20A, 20B generally extend in adorsal-palmar direction from the third or top side including the grooves38A, 38B about the non-threaded apertures 20A, 20B to the fourth orbottom side.

As also shown in FIGS. 15 and 16, the fusion device 70 may preferably bepositioned generally intermediate in the target fusion bones in thedorsal-palmar direction. When used with the wrist, as illustrated inFIGS. 15 and 16, the device 70 may be angled in the distal-palmardirection from the first end 12 to the second end 14 and from the heads54 of the fusion members 50A, 50B to the rear or distal surface of thebody 16. The fusion implant 10 may be positioned in the medial-lateraldirection such that the first internally threaded aperture 18A and thefirst fusion member 50A coupled thereto are positioned in the secondbone B1, and at least one of the second and third internally threadedapertures 18B, 18C and at least the second fusion member 50B coupledthereto are positioned in the adjacent first bone, as shown in FIGS. 15and 16. In such a construct, the positioning and orientation (e.g., therelative angles θ3, θ4 of the axes Z1-Z1, Z2-Z2) of the internallythreaded apertures 18A-C preferably result in the fusion members 50A,50B being positioned and oriented in intermediate positions in themedial-lateral direction of the third B3 and fourth B4 bones.

The fusion implant 10 may also be positioned intermediate in the firstbone B1 and the second bone B2 in the proximal-distal direction, asshown best in FIG. 16. The proximal-distal positioning of the implant 10and/or the lengths L13, L17 and L16 of the first threaded portion 56,second threaded portion 60 and non-threaded portion 58, respectively, ofthe fusion members 50A, 50B may be configured such that when the firstthreaded portion 56 of the fusion members 50A, 50B is threadably engagedwith the internally threaded apertures 18A-C of the fusion implant 10,the first threaded portion 56 is at least primarily positioned in thefirst bone B1 or second bone B2 and the second threaded portion 60 is atleast primarily positioned in the third bone B3 or fourth bone B4. Insome embodiments, the proximal-distal positioning of the implant 10and/or the relative lengths L13, L17 and L16 of the first and secondthreaded and non-threaded portions 56, 60, 58, of the fusion members50A, 50B may be configured such that when the first threaded portion 56of the fusion members 50A, 50B is threadably engaged with the internallythreaded apertures 18A-C of the fusion implant 10, the first threadedportion 56 is only positioned in the first bone B1 or second bone B2,the second threaded portion 60 is only positioned in the third bone B3or fourth bone B4, and the non-threaded portion spans the joint betweenthe first and third bones B1, B3 or the second and fourth bones B2, B4.

FIGS. 17 and 18 illustrate an exemplary instrument for use inpositioning a fusion implant, such as fusion implant 10, into at leastone bone to obtain a bone fusion in an upper extremity of a patient. Theinstrument is an exemplary guide clamp 100 that includes an exemplaryfirst arm 102 and an exemplary second arm 104. The first and second arms102, 104 are pivotably or rotatably coupled to each other atintermediate points thereof. In the illustrated embodiment, the couplingmechanism 120 between the first arm 102 and the second arm 104 is anexemplary hinge or pin 120. The first arm 102 may also include anexemplary first manually engageable member 122A spaced from the pivotpoint 120, and the second arm 104 may include an exemplary secondmanually engageable member 122B spaced from the pivot point 120. In theillustrated embodiment, the manually engageable members 122A, 122B areapertures sized and shape to allow a user to pass a portion on a fingertherethrough.

The first arm 102 may also include a first ratcheting member 124A andthe second arm 104 may include a second ratcheting member 124, and thefirst and second ratcheting members 124A, 124B may be engaged with eachother. Engagement of the first and second ratcheting members 124A, 124Bmay prevent movement of the first and second arms 102, 104 in one degreeof freedom allowed by the coupling mechanism 120. For example, the firstand second arms 102, 104 and coupling mechanism 120 may be configured toallow two degrees of freedom between the first and second arms 102, 104such that the manually engageable members 122A, 122B are able to move ina first direction towards each other and a second direction away fromeach other. In such an embodiment, the first and second ratchetingmembers 124A, 124B may be configured to prevent movement in the seconddirection. In the illustrated embodiment, the first and secondratcheting members 124A, 124B include teeth configured to mate andprevent movement in the second direction (a direction in which themanually engageable members 122A, 122B move away from one another). Insuch a configuration, the guide clamp 100 can be used as a scissor-likeclamp.

The exemplary first arm 102 may further include an exemplary guidemember 106 rotatably coupled thereto. The exemplary guide member 106 maybe spaced from the first manually engageable member 122A and on anopposing side of the coupling mechanism 120 as compared to the firstmanually engageable member 122A. The guide member 106 may include alongitudinally extending member or barrel 107 including a first boneabutment surface 108 and an aperture extending linearly andlongitudinally therethrough defining a longitudinal axis X3-X3, as shownin FIG. 17. The longitudinal axis X3-X3 of the aperture can therefore beconsidered the longitudinal axis of the guide member 108 and/or themember or barrel 107 of the guide member 108.

The longitudinally extending aperture of the barrel 107 of the guidemember 106 may be sized and shaped to allow a drill bit therethrough.The longitudinally extending aperture may further be sized and shaped toguide a drill bit along the longitudinal axis X3-X3. In the illustratedembodiment, the longitudinally extending aperture of the barrel 107 ofthe guide member 106 is shaped and sized to receive a drill bitcorresponding to the shape and size of the fusion implant 10 describedabove, and to align and guide the longitudinal axis of the drill bitwith the longitudinal axis X3-X3 of the aperture of the guide member106. As shown in FIG. 18, in such an arrangement the drill bit maycreate a fusion implant aperture or cavity X4 that is sized and shapedto accept the fusion implant 10 therein. As such, in the illustratedembodiment the longitudinally extending aperture of the barrel 107 ofthe guide member 106 is circular or cylindrical and defines a diameterof about 0.95 inch. As the guide member 106 is rotatably coupled to thefirst arm 102, the longitudinal axis X3-X3 of the aperture of the guidemember 106 is also rotatable with the first arm 102.

The guide member 106 may also include a first bone abutment surface 108on an outer surface of the barrel 107 configured to abut or otherwiseengage a first outer surface of a first bone. In the illustratedembodiment, the exemplary first abutment surface 108 includes aprojection or spike extending from the outer surface of the barrel 107of the guide member 106. The exemplary spike of first bone abutmentsurface 108 extends in a direction generally along the direction oflongitudinal axis X3-X3. In such an embodiment, the projection of thefirst abutment surface 108 may be sized and shape to penetrate or extendinto the first outer surface of the first bone. In such an arrangement,the projection of the first abutment surface 108 may stabilize thelocation and orientation of the barrel 107, and thus the longitudinalaxis X3-X3, of the guide member 106 at the first bone. Ultimately, thefirst abutment surface 108 may stabilize the location and orientation ofa drill bit passing through the barrel 107 at the first bone. In such anarrangement, other outer surfaces of the barrel 107, instead of or inaddition to the projection, may form the first abutment surface 108. Forexample, the illustrated projection or spike extending from the outersurface of the barrel 107 may penetrate and extend into a first outersurface of the first bone, and upon such penetration other surfaces ofthe barrel 107 may contact the first surface of the first bone, asillustrated in FIG. 18. As such, the outer surfaces of the barrel 107may generally be considered the first abutment surface 108 (i.e., theprojection or spike may be part of the first abutment surface 108). Insome alternative embodiments, the first abutment surface 108 does notinclude the projection or spike. The guide member 106 may provide avisual and tactile indication of the location of the longitudinal axisX3-X3 of the aperture of the guide member 106 at the first outer surfaceof the first bone.

The exemplary second arm 104 may include an exemplary bone abutmentmember 110 rotatably coupled thereto, as shown in FIGS. 17 and 18. Thebone abutment member 110 may preferably be configured to engage theouter surface of a second bone that is adjacent and spaced from thefirst bone, as shown in FIG. 18. The exemplary bone abutment member 110may be spaced from the second manually engageable member 122B and on anopposing side of the coupling mechanism 120 as compared to the secondmanually engageable member 122B. The bone abutment member 110 mayinclude an exemplary second bone abutment surface 112 and an exemplarythird bone abutment surface 114 configured to abut or otherwise engageat least one second outer surface of a second bone. For example, theexemplary bone abutment member 110 may be positioned and oriented suchthat the second and third bone abutment surfaces 112, 114 abut orotherwise engage a second outer surface of a second bone thatsubstantially opposes the first outer surface of the first bone and atop or dorsal outer surface of the second bone, as shown in FIG. 17. Asbest shown in FIG. 17, the exemplary second bone abutment surface 112 ofthe exemplary bone abutment member 110 may be a member or surfaceextending longitudinally in a direction generally along the direction ofthe longitudinal axis X3-X3 of the guide member 106 of the first arm102. In such an arrangement, the second bone abutment surface 112 may beconfigured to abut or engage a top or dorsal outer surface of the secondbone, as shown in FIG. 18.

Similarly, the exemplary third bone abutment surface 114 of theexemplary bone abutment member 110 may be a member or surface. However,the third bone abutment surface 114 may extend in a lateral directionsuch that it intersects the longitudinal axis X3-X3 of the aperture ofthe guide member 106 of the first arm 102. In the illustratedembodiment, the third bone abutment surface 114 includes a projection orhook 116 that includes a point that intersect the longitudinal axisX3-X3 of the aperture of the guide member 106 of the first arm 102. Insuch an arrangement, the third bone abutment surface 114, including theprojection 116, may thereby be configured to engage the second outersurface of the second bone that substantially opposes the first outersurface of the first bone, as shown in FIG. 18. The lateral location ofthe projection or hook 116 of the third bone abutment surface 114 on thesecond bone may thereby depend upon the lateral length L18 of the thirdbone abutment surface 114 from the second bone abutment surface 112(because the second bone abutment surface 112 is configured to contactthe top or dorsal surface of the second bone), as shown in FIG. 18. Asthe projection 116 of the third bone abutment surface 114 intersects thelongitudinal axis X3-X3 of the aperture of the guide member 106 of thefirst arm 102, the lateral length L18 is determinative of thedorsal-palmar location or orientation of an implant cavity formed in thebones via the guide member 106.

In the illustrated embodiment, the guide clamp 100 is particularly wellsuited for facilitating the forming of an implant cavity in the hammateand capitate bones of the wrist, and the projection 116 of the thirdbone abutment surface 114 is configured to sit within a detent in theouter surface of the hammate bone, such as at the tubercle or depressionlocated at the capitate-trapezoid articulation. In such an embodiment,the lateral length L18 between the second bone abutment surface 112 andthe projection 116 of the third bone abutment surface 114 is preferablyabout 0.3 inch.

As the projection 116 of the third bone abutment surface 114 intersectsthe longitudinal axis X3-X3 of the aperture of the guide member 106 ofthe first arm 102, the projection 116 provides a visual and tactileindication of the location of the longitudinal axis X3-X3 of theaperture of the guide member 106 at the second outer surface of thesecond bone, as shown in FIG. 18. As such stated above, the guide member106 provides a visual and tactile indication of the location of thelongitudinal axis X3-X3 of the aperture of the guide member 106 at thefirst outer surface of the first bone. Therefore, the exemplary guideclamp 100 can be used to create an implant cavity X4 spanning spacedadjacent bone, such as the hammate and capitate bones, and the positionand orientation of the implant cavity X4 can be tactilely and visuallyindicated by the guide clamp 100 before the implant cavity X4 is formedin the bones. Further, as the illustrated projection 16 of the abutmentmember 110 of the second arm is configured to couple to a particularpredefined location of the outer surface of the second or hammate bone,the guide member 106 of the second arm 14 can be selectively positionedon the outer surface of the first or capitate bone in reference to thelongitudinal axis X3-X3 of the barrel 107 so that the implant cavity X4formed by way of the aperture of the barrel 107 (and the fusion implant10 implanted therein) passes through the bones (such as the hammate andcapitate bones) in a medial-lateral direction in intermediate portionsin dorsal-palmar and distal-proximal directions, as shown in FIGS. 15,16 and 18.

As discussed above, the guide member 106 may be rotatably coupled to thefirst arm 102, and the abutment member 110 may rotatably coupled to thesecond arm 104. In such an arrangement, the guide clamp 100 may beconfigured such that the longitudinal axis X3-X3 of the guide member 106is aligned with the projection 116 of the abutment member 110, such asto provide the tactile and visual indication of the positioning andorientation of the implant cavity X4 formed or facilitated by the guidemember 106. In embodiments particularly configured for use with thehammate and capitate bones of the wrist, the alignment of thelongitudinal axis X3-X3 of the guide member 106 with the projection 116of the abutment member 110 is particularly critical because theprojection 116 is configured to couple to a predefined point of thehammate bone determined to provide an advantageous position andorientation of the implant cavity X4. Stated differently, the projection116 can be used as a standard pre-determined reference point from whichthe position of the guide clamp 100 can be based. Thus, maintainingalignment of the axis X3-X3 of the guide member 106 with the abutmentmember 110, and therefore the axis of the implant cavity X4, isadvantageous.

In the illustrated embodiment, the guide clamp 100 includes apositioning member 118 that maintains the orientation of the guidemember 106 and abutment member 110 during movement of the first andsecond arms 102, 104 such that the longitudinal axis X3-X3 of the guidemember 106 aligns with the projection 116 of the abutment member 110during movement of the first and second arms 102, 104 relative to eachother. Stated differently, the positioning member 118 maintains analigned orientation between the guide member 106 and abutment member110. The “aligned orientation” therefore refers to the alignment of thelongitudinal axis X3-X3 of the guide member 106 with the projection 116of the abutment member 110.

As shown in FIGS. 17 and 18, the positioning member 118 is an elongatemember coupled to a post of each of the guide member 106 and theabutment member 110. The positioning member 118 is slidably coupled toat least one of the posts of the guide member 106 and the abutmentmember 110 and fixedly coupled to the other post of the guide member 106and the abutment member 110. In the illustrated embodiment, thepositioning member 118 is slidably coupled the abutment member 110 andfixedly coupled to the guide member 106. In such an arrangement, whenthe first and second arms 102, 104 are rotated about the couplingmechanism 120, the guide member 106 and the abutment member 110 movetoward or away from each other, depending upon the direction of themovement, along an arc about the coupling mechanism 120. As the guidemember 106 and the abutment member 110 move along their arcuate paths,the positioning member 118 slides within the post of the abutment member110 and forces the posts of the guide member 106 and the abutment member110 to rotate with the first and second arms 102, 104, respectively, tomaintain the aligned orientation of the guide member 106 and theabutment member 110.

FIG. 18 shows the exemplary guide clamp 100 of FIGS. 17 and 18 in usewith the hammate and capitate bones of the wrist. As shown in FIG. 18,the manually engageable members 122A, 122B can be engaged and the firstand second arms 102, 104 pivoted with respect to one another to clampthe hammate and capitate bones between the guide member 106 and theabutment member 110. The positioning member 118 can maintain the alignedorientation of the guide member 106 and the abutment member 110 duringsuch pivoting (i.e., the longitudinal axis X3-X3 of the guide member 106is maintained in alignment with the projection 116 of the abutmentmember 110). In such a position, the teeth of the first and secondratcheting members 124A, 124B can prevent the first and second arms 102,104 from pivoting away from each other, and therefore maintain theclamped position of the first and second arms 102, 104. As also shown inFIG. 18, the first bone abutment surface 108 may be clamped such that itabuts or engages the outer surface of the capitate, such as theprojection being pushed into the capitate and the remaining portion ofthe abutment surface 108 being abutted against the outer surface of thecapitate. Similarly, the projection 116 of the third bone abutmentsurface 114 of the bone abutment member 110 can be clamped such that itcouples in the detent of the outer surface of the hammate bone, theremaining portion of the third bone abutment surface 114 abuts with theouter surface of the hammate, and the second bone abutment surface 112abuts with the top or dorsal outer surface of the hammate. In such anorientation, the implant cavity X4 can be formed via the guide member106 in intermediate portions of the hammate and capitate.

FIGS. 19-21 illustrate an exemplary instrument for use in positioning afusion implant and fusion members into adjacent bones to obtain bonefusion in an upper extremity of a patient. The exemplary instrument isan exemplary targeting guide 200 that includes an exemplary fusionimplant 210, an exemplary targeting member 250, at least one exemplaryguide member 265, and an exemplary outrigger member 280. The exemplaryfusion implant 210 is substantially the same as the exemplary fusionimplant 10 described above with reference to FIGS. 1-8 and 12-16, andtherefore like reference numerals preceded by the numeral “2” are usedto indicate like elements. The description presented above with respectto fusion implant 10 of FIGS. 1-8 and 12-16 therefore equally applies tofusion implant 210, but is not repeated here for brevity purposes.

As best shown in FIGS. 19 and 20, the exemplary targeting member 250includes at least one arm that couples to the exemplary at least oneguide member 265 and the exemplary outrigger member 280. In oneembodiment, the targeting member 250, the guide members 265 and themember 280 are monolithic. The exemplary targeting member 250 mayinclude at least one bone anchor aperture extending through thetargeting member 250 such that a bone anchor can pass through thetargeting member 250 and into a bone. The at least one bone anchoraperture thereby allows the targeting member 250, and therefore thetargeting guide 200, to be coupled or fixed to a bone via a bone anchor.A bone anchor may take any form capable of acting as a bone anchor. Forexample, the bone anchor may be a k-wire, screw, nail, or wire. In theillustrated embodiment, the exemplary targeting member 250 includes twobone anchor apertures 252A, 252B extending therethrough defining axesY2-Y2. The bone anchor apertures 252A, 252B are configured to accept ak-wire therethrough. As a result, the bone anchor apertures 252A, 252Bare circular or cylindrical and define a diameter substantially similarto known standard k-wire sizes. For example, the first and second boneanchor apertures 252A, 252B may define a diameter of about 0.63 inches.

In the illustrated embodiment, a first bone anchor aperture 252A ispositioned proximate one end of the targeting member 250, and a secondbone anchor aperture 252A is spaced from the first bone anchor andpositioned on an intermediate portion of the targeting member 250. Thefirst and second bone anchor apertures 252A, 252B are preferablypositioned and oriented such that they align with the first and secondnon-threaded apertures 220A, 220B of the fusion implant 210 when thefusion implant 210 is coupled to the outrigger member 280 in a first or“proper” orientation, as described further below. This may beaccomplished through the configuration of the targeting member 250, theoutrigger member 280 and the relative positioning of the first andsecond bone anchor apertures 252A, 252B themselves in the targetingmember 250, as well as the positioning and orientation of the first andsecond non-threaded apertures 220A, 220B in the fusion implant 210. Asshown in FIG. 19, the axes Y2-Y2 of the illustrated first and secondbone anchor apertures 252A, 252B are substantially aligned with the axesY1-Y1 of the first and second non-threaded apertures 20A, 20B,respectively of the fusion implant 210.

Therefore, in such an arrangement, when the fusion implant 210 isimplanted in multiple bones such that the first non-threaded aperture220A is positioned in a first bone and the second non-threaded aperture220B is positioned in a second bone adjacent the first bone, a firstbone anchor can be inserted through the first bone anchor aperture 252Aof the targeting member 250, into the first bone, and into the firstnon-threaded aperture 220A of the fusion implant 220. Similarly, in sucha construct, a second bone anchor can be inserted through the secondbone anchor aperture 252B of the targeting member 250, into the secondbone, and into the second non-threaded aperture 220B of the fusionimplant 220 (see FIGS. 23 and 29). In this way, the first and secondbone anchor apertures 252A, 252B can couple or fix the targetinginstrument 200, fusion implant 210 and first and second bones withrespect to one another via the first and second bone anchors 252A, 252B.The positioning, orientation, shape and size of the first and secondbone anchors 252A, 252B is thereby dependent upon the positioning,orientation, shape and size of the first and second non-threadedapertures 220A, 220B of the fusion implant 210, or vice versa. As such,when the targeting instrument 200 includes the fusion implant 210 ofFIGS. 1-8 and 12-16 coupled in the first or “proper” orientation, theabove described positioning, orientation, shape and size of the firstand second non-threaded apertures 220A, 220B and their axes Y1-Y1equally applies to the first and second bone anchors 252A, 252B andtheir axes Y2-Y2.

The targeting member 250 may include at least one clamp member 254configured to receive a clamp thereon to secure or couple another boneanchor to the targeting member 250, and therefore to the targetinginstrument 200. In the illustrated embodiment, the targeting member 250of the targeting instrument 200 includes two clamp members, a firstclamp member 254A positioned adjacent the first bone anchor aperture252A at a first axial side portion of the targeting member 250, and asecond clamp member 254B spaced from the first clamp member 254A and thesecond intermediate bone anchor aperture 252B at a second axial sideportion of the targeting member 250 (with respect to the axis X-X of thefusion implant 210). The first clamp member 254A is positioned such thatthe first bone anchor aperture 252A passes through a portion of thefirst clamp member 254A but does not interfere with the functioning ofthe first clamp member 254A. In some alternative embodiments, the firstand second clamp members 254A, 254B are formed into, or are a part of,the targeting member 250 (rather than projecting from the targetingmember 250 as illustrated). In some such embodiment, the first andsecond clamp members 254A, 254B are formed into, or are a part of, alower (plantar) portion of the targeting member 250. In some alternativeembodiments, the first and second clamp members 254A, 254B project forma lower (plantar) surface of the targeting member 250.

Each of the first and second clamp members 254A, 254B may include aribbed or slotted surface. In the illustrated embodiment, each of thefirst and second clamp members 254A, 254B include a slotted surface on adistal side of the first and second clamp members 254A, 254B, and theslots extending generally in a dorsal-palmar direction. In someembodiments, the slots of the slotted surface are “V” shaped grooves inthe surface. In alternative embodiments, the slots of first and secondclamp members 254A, 254B extend in a direction other than generally in adorsal-palmar direction, and are configured on any side of the clampmembers 254A, 254B. Each of the first and second clamp members 254A,254B may also include an aperture 255A, 255B extending through theslotted surface, as shown best in the illustrated embodiment in FIGS. 19and 20. In arrangements including first and second clamp members 254A,254B with such apertures and slotted surfaces, the first and secondclamp members 254A, 254B may be configured to accept a clamp through theaperture and into the slotted surface, as described below. As alsodescribed further below, the slots of the slotted surface may preventrotation of a clamp associated with the first and second clamp members254A, 254B, and therefore angulation or rotation of the bone anchors andbones secured thereby.

As shown in FIGS. 19 and 20, the first and second clamp members 254A,254B are curved or radiused such that the slotted surface is of a convexshape. Such an arrangement allows a clamp to couple to the first andsecond clamp members 254A, 254B via the curved slotted surface innumerous different positions and orientations depending upon theposition or orientation of a particular bone anchor. As such, the clampcan be positioned and oriented in a manner that facilitates a securecoupling with a particular bone anchor, and therefore a secure couplingof the bone anchor to the targeting member 250 and targeting instrument200, as described further below.

An outrigger member 280 may be coupled to the targeting member 250 by anarm extending from the outrigger member 280 to the targeting member 250.In such arrangements, the arm coupling the outrigger member 280 and thetargeting member 250 may be considered part of the targeting member 250,part of the outrigger member 280, or the targeting member 250 and theoutrigger member 280 may both include a portion of the arm. As shownbest in FIGS. 20 and 21, the outrigger member 280 may couple to thefirst end 212 of the fusion implant 210.

As shown in FIGS. 20 and 21, the outrigger member 280 may include an endportion that is shaped and sized to receive, couple or mate with thefirst end 212 of the fusion implant 210. Specifically, in theillustrated embodiment, the outrigger member 280 includes the shape(cylindrical) of the fusion implant 210 and an end profile that mimicsor mirrors the profile of the first end 212 of the fusion implant 210,but in reverse. In such embodiments, the above described configurationof the first end 12 of the fusion implant 10 equally applies to theconfiguration of the profile of the outrigger member 280, but in areversed or mirrored configuration so that the outrigger member 280 canmate with the first end 212. As described above, the skewed oroff-center profile or configuration of the first end 212 of the fusionimplant 210 allows the fusion implant 210 to be coupled to such anoutrigger member 280 in only two orientations—an “improper” orientationand a “proper” orientation. Further, the skewed or off-center profile orconfiguration of the first end 212 provides a visual or tactileindication when it is configured in an “improper” orientation with theoutrigger member 280, as compared with the “proper” orientation. In theillustrated embodiment, as the profile or configuration of the first end212 of the fusion implant 210 and the end of the outrigger member 280take skewed or off-center “V” shapes (e.g., when viewed from the distaldirection), with one leg of the “V” being longer than the other leg, theouter surfaces of the fusion implant 210 and the outrigger member 280will be skewed or otherwise not aligned when they are coupled or matedin the “improper” orientation. As shown best in FIG. 20, the first end212 of the fusion implant 210 and the end of the outrigger member 280are coupled in the “proper” orientation and the outer surfaces of thefusion implant 210 and the outrigger member 280 are aligned and even.

Further, as described above the first end 212 of the fusion implant 210includes a threaded aperture 240 (not shown) extending longitudinallyabout the axis X-X of the fusion implant 210 (see FIGS. 7 and 8).Similarly, the outrigger member 280 includes an aperture (not shown)that extends longitudinally through the outrigger member 280 defining anaxis X5-X5. The axis X5-X5 of the aperture of the outrigger member 280is configured to align with the axis X-X of the aperture of the firstend 212 of the fusion implant 210 when the fusion implant 210 is coupledto the outrigger member 280 in the “proper” orientation. In such anorientation, as shown in FIGS. 19-21, a threaded tightening bolt 282 canbe received within the longitudinally extending aperture of theoutrigger member 280 and into threaded engagement with the internalthreading 242 (not shown) of the longitudinally extending aperture 240(not shown). By including a stop surface configured to contact the outersurface of the outrigger member 280 opposing the first end 212 of thefusion implant 210, the tightening bolt 282 can be rotated and the firstend 12 of the fusion implant 210 pulled into engagement with theoutrigger member 280. Further rotation of the tightening bolt 282 willsecurely selectively couple the fusion implant 210 to the outriggermember 280 in the “proper” orientation.

As described further below, by securing the fusion implant 210 in such apredefined orientation, the aspects of the targeting instrument 200 canbe designed or configured to align, cooperate or engage with particularaspects of the fusion implant 210. For example, as explained above, thefirst and second bone anchor apertures of the 252A, 252B of thetargeting member 250 preferably align with the first and secondnon-threaded apertures 220A, 220B of the fusion implant 210,respectively. As shown in the illustrated embodiment, the coupling ofthe fusion implant 210 to the outrigger member 280 in the “proper”orientation ensures that the first and second bone anchor apertures252A, 252B align with the first and second non-threaded apertures 220A,220B, respectively.

The off-center or skewed profile of the first end 212 of the fusionimplant 210, as well as the profile of the end of the outrigger member280, will also prevent the alignment of the longitudinally extendingapertures of the outrigger member 280 and fusion implant 210 when theoutrigger member 280 and the fusion implant are coupled in the“improper” orientation (they will be askew). As such, the configurationor profile of the outrigger member 280 and first end 212 of the fusionimplant 210 prevents the instrument 200 and the fusion implant 210 to beselectively or removably coupled to one another in any orientation otherthan the “proper” orientation via the threaded tightening bolt 282.

As illustrated in FIGS. 19-21, the at least one guide member 265 may becoupled to the targeting member 250 by an arm extending from the atleast one guide member 265 to the targeting member 250. In sucharrangements, the arm coupling the at least one guide member 265 and thetargeting member 250 may be considered part of the targeting member 250,part of the at least one guide member 265, or the targeting member 250and the at least one guide member 265 may both include a portion of thearm. As shown best in FIG. 19, constructs including multiple guidemembers 265 may include multiple arms coupling the guide members 265 tothe targeting member 250.

In the illustrated embodiments, the targeting instrument 200 includestwo guide members 265 laterally spaced (spaced in a proximal-distaldirection) from the outrigger member 280 and the fusion implant 210coupled thereto, with respect to the longitudinal axis X-X of the fusionimplant 210. The guide members 265 are also longitudinally spaced formone another with respect to the longitudinal axis X-X of the fusionimplant 210. The two guide members 265 define at least one guide tube orbarrel that includes elongate laterally extending guide aperturesdefining axes that extend laterally (in a proximal-distal direction),with respect to the longitudinal axis X-X of the fusion implant 210.

As shown in FIGS. 19-21, the guide members 265 define a first laterallyextending guide aperture 268A defining an axis Z3-Z3, and second andthird laterally extending guide apertures 268B, 268C defining axesZ4-Z4. The target instrument 200 is preferably configured such that,when the fusion implant is coupled in the first or “proper” orientationwith the outrigger member 280, the axis Z3-Z3 of the first guideaperture 268A is aligned with the axis Z1-Z1 of the first internallythreaded aperture 218A of the fusion implant 210, the axis Z4-Z4 of thesecond guide aperture 268B is aligned with the axis Z2-Z2 of the secondinternally threaded aperture 218B of the fusion implant 210, and theaxis Z4-Z4 of the third guide aperture 268C is aligned with the axisZ2-Z2 of the third internally threaded aperture 218C of the fusionimplant 210. In such an embodiment, at least the positioning andorientation of the first, second and third guide apertures 268A-C arethereby dependent upon the positioning and orientation of the first,second and third threaded apertures 218A-C, respectively, of the fusionimplant 210, or vice versa. As such, when the targeting instrument 200includes the fusion implant 10 of FIGS. 1-8 and 12-16 coupled in the“proper” orientation, at least the above described positioning andorientation of the threaded apertures 18A-C and their respective axesZ1-Z1 and Z2-Z2 equally applies to the guide apertures 268A-C and theirrespective axes Z3-Z3 and Z4-Z4, but is not repeated herein for brevitypurposes.

In such an arrangement, as illustrated in FIGS. 19-21, the guideapertures 268A-C of the at least one guide member 265 can facilitate thedrilling of cavities through bone or bones to the internally threadedapertures 218A-C of the fusion implant 210, as shown in FIGS. 22 and 23.For example, as show in FIGS. 19 and 20, the at least one guide member265 is laterally spaced from the fusion implant along the axes Z1-Z1,Z2-Z2 of the internally threaded apertures 218A-C, and therefore theaxes Z3-Z3 and Z4-Z4 of the guide apertures 268A-C of the at least oneguide member 265. In such a spaced relationship, when the fusion implant210 is coupled to the outrigger member 280 in the “proper” orientationand inserted into a fusion implant cavity in adjacent first and secondbones, for example, the targeting instrument 200, and therefore thefusion implant 210, can be rotated about the longitudinal axis X-X ofthe fusion implant 210 and into an orientation such that third andfourth bones adjacent the first and second bones are positioned betweenthe fusion implant 201 and the at least one guide member 265, as shownin FIGS. 22 and 23. The targeting instrument 200 and fusion implant 210may then be secured to the first, second, third or forth bones utilizingthe first and second clamp member 252A, 252B and the first and secondbone anchor apertures 252A, 252B, as described further below and shownin FIGS. 22 and 23.

In such a configuration or orientation, first, second and third drillbushings 270A-C may be coupled to the first, second and third guideapertures 268A-C, respectively, as shown in FIGS. 19 and 21. As thesecond and third internally threaded apertures 218B, 218C may besubstantially parallel and in close proximity, the second and thirddrill bushings 270A, 270B may be combined into a single bushing thatincludes two sub-bushing members corresponding to the second and thirddrill bushings 270A, 270B, as shown in the illustrated embodiment. Thedrill bushings 270A-C preferably define laterally extending apertures ofa diameter less than the diameter of the at least one guide member 265,and apertures defining axes that are aligned with the axes Z3-Z3 andZ4-Z4 of the guide apertures 268A-C. In such an arrangement, the axes ofthe drill bushings 270A-C align with the axes Z1-Z1, Z2-Z2 of theinternally threaded apertures 218A-C of the fusion implant 210. As such,a drill bit can be inserted into the drill bushings 270A-C, and thedrill bushings 270A-C used to guide the drill bit through the first,second, third and fourth bones to the internally threaded apertures218A-C of the fusion implant 210, as shown in FIGS. 22 and 23.

As the distance along the axes Z3-Z3 and Z4-Z4 of the guide apertures268A-C between the internally threaded apertures 218A-C of the fusionimplant 210 and the outer edges of the at least one guide member 265,for example, are constant distances, a depth gauge (not shown) can beinserted into the at least one guide member 265 before the drillbushings 270A-C are coupled thereto and used to determine the distancebetween such a fixed point the internally threaded apertures 218A-C ofthe fusion implant 210. Based on the depth reading taken from the depthgauge, particular drill bushings 270A-C providing a stop surfacecorresponding to the depth of the internally threaded apertures 218A-Cof the fusion implant 210 being used may be inserted into the at leastone guide member 265 before the drilling process. Then, during thedrilling process, the drill bit 290 may be guided by the particulardrill bushings 270A-C and particular drill bushings 270A-C to the stop,such that the tip of the drill bit 290 is extended to the internallythreaded apertures 218A-C of the fusion implant 210, as shown in FIGS.22 and 23. It is noted that tolerances involved in the machining andmanufacturing process may result in the drill bit 290 coming very closeto the internally threaded apertures 218A-C, such as about 2 millimetersaway, or the drill bit 290 may enter the internally threaded apertures218A-C slightly.

Once the drilling process is complete, the drill bushings 270A-C may beremoved from the at least one guide member 265, as shown in FIGS. 22 and23. As also shown in FIGS. 22 and 23, a fusion member, such as theexemplary bone screw 50 described above, may then be inserted into eachof the guide members 265 and guided thereby into the formed fusionmember cavities corresponding to the internally threaded apertures218A-C of the fusion implant 210. A driver 295 may then be used torotatably advance the fusion members into the corresponding bones and,eventually, into threaded engagement with the internally threadedapertures 218A-C of the fusion implant 210, as shown in FIGS. 22 and 23.

As described above, the targeting instrument 200 and fusion implant 210may be secured to the first, second, third and/or fourth bones utilizingat least one clamp before the drilling process is completed. Anexemplary embodiment of a clamp for use with the first and second clampmembers 254A, 254B of the targeting member 250 is illustrated in FIGS.24-28. As shown best in FIGS. 24 and 25, the exemplary illustrated clamp300 includes a hook member 301. The hook member 301 is configured topass at least partially through the apertures 255A, 255B of the firstand second clamp members 254A, 254B of the targeting member 250. Thehook member 301 is an elongate “J” shaped member including an elongateshaft-like member 302 and a head portion 303 at one end of the shaft302. The shaft 302 may include exterior threading and an interioraperture extending through the shaft 302 to the head portion 303. In theillustrated embodiment, the interior aperture includes internal threads.The head member 303 may be a “U” shaped member defining an interiorarcuate channel 305 and an access member 304 that extends from thearcuate channel 305 towards the shaft 302. The access member 304 may notextend fully back to the shaft 302, thereby creating a pathway into theinterior of the head member 303 and the arcuate channel 305. Theinternally threaded aperture of the shaft 302 extends to the interior ofthe head member 303 such that the axis defined by the internallythreaded aperture intersects the arcuate channel 305. In use, the headmember 303 may pass through the apertures 255A, 255B of the first andsecond clamp members 254A, 254B. For example, as shown in FIG. 25, thehead member 303 may pass through the aperture 255B of the second clampmember 254B such that the interior arcuate channel 305, access member304, and pathway defined by the access member 304 are located on theside of the second clamp member 254B that is void of slots or grooves,and the shaft 302 extends on the opposing side of the of the secondclamp member 254B that includes the slots or grooves.

As shown in FIG. 25, in such an arrangement a bone anchor 350 may beimplanted into a bone and then moved through the pathway formed by thehead portion 303 and access member 304 and into the interior of the headportion 303 and within the arcuate channel 305. In some embodiments, thebone anchor 350 is manipulated into the interior of the head portion303, and in other embodiments the hook member 301 is manipulated suchthat the bone anchor 350 is passed into the interior of the head portion303. The pathway formed by the access member 304 and the other portionsof the head portion 303 therefore is preferably sized and shaped toallow the bone anchor 350 therethrough. In the illustrated embodiment,the bone anchor 350 is a 1.6 millimeter k-wire, and therefore thepathway is at least about 0.63 inch wide.

As shown in FIG. 26, once the bone anchor 350 is positioned in theinterior of the head portion 303, an elongate compression member 306 maybe coupled to the internally threaded aperture of the shaft 302 of thehook member 301. As such, the compression member 306 is preferablyshaped and sized to engage the internal threads of the interior apertureof the shaft 302 of the hook member 301. As shown in FIG. 26, thecompression member 306 may also include a manually engageable member 310for manual rotation of the compression member 306 within the shaft 302.The compression member 306 is also preferably sized such that the end312 of the compression member 306 is capable of threading through theshaft 302, into the interior of the head portion 303 and at leastadjacent to the arcuate channel 305, as best shown in FIGS. 24 and 28.In such a configuration, as shown in FIG. 26, the compression member 306may be rotationally advanced within the shaft 302 of the hook member 301such that the end 312 of the compression member 306 engages the boneanchor 350 and compresses the bone anchor 350 against the arcuatechannel 305. As such, the compression member 306 may be effective insecuring the bone anchor 350 to the hook member 301 (as the bone anchor350 is compressed between the end 312 of the compression member 306 andthe arcuate channel 305, and the compression member 306 is carriedwithin the hook member 301). As such, the bone anchor 350 can beinserted into a bone, and used as a joystick to reorient or repositionthe bone. Once a satisfactory orientation and position of the bone isachieved, the orientation and position can be “locked” by securing thebone anchor 350 to the hook member 301, and further securing the hookmember 301 to the clamp members 254A, 254B as discussed below.

Movement of the bone anchor 350, the hook member 301 and compressionmember 306, may be restricted through the use of a washer member 312, asshown in FIGS. 27-29. The washer member 312 may include an aperturetherethrough and at least one rib 314 extending from a bearing surface.The washer member 312 may preferably be configured to pass over thecompression member 306 and shaft 302 of the hook member 301 via theaperture. As shown in FIGS. 27-29 in such a configuration the at leastone rib 314 of the washer member 312 may engage the channels or groovesof the ribbed or slotted surface of the second clamp member 254B. Insome embodiments, the at least one rib 314 is a “V” shaped rib 314configured to mate with “V” shaped grooves on the ribbed or slottedsurface of the second clamp member 254B. The washer member 312 may alsoengage the head portion 303 and/or the shaft 302 of the hook member 301.

As show in FIG. 28, once the at least one rib 314 of the washer member312 is engaged with a channel or groove of the ribbed or slotted surfaceof the second clamp member 254B, a nut 316 may threadably engaged withthe outer threading of the shaft 302 of the hook member 301. In suchembodiments, the nut 316 may preferably include an internally threadedaperture configured to threadably engage the outer threading of theshaft 302 of the hook member 301. The nut 316 can be rotationallyadvanced along the shaft 302 of the hook member 301 and into abutmentwith the washer member 312. The nut 316 may therefore lock the washermember 312, and the at least one rib 314, against the ribbed or slottedsurface of the second clamp member 254B. As the washer member 312 andnut 316 are larger than the aperture of the ribbed or slotted surface ofthe second clamp member 254B, the construct including the hook member301, compression member 306 and bone anchor 350 is prevented frommovement in a direction from the head portion 303 to the shaft 302 ofthe hook member 301. Further, the construct may be secured to the secondclamp member 254B and the bone anchor 350 such that movement of the boneanchor, and the bone coupled thereto, is substantially prevented in thedorsal-palmar direction.

In some embodiments, the nut 316 may be rotated to such a degree thatthe nut 316 compresses the washer member 312 against the ribbed orslotted surface of the second clamp member 254B. In some suchembodiments, the washer member 312 may be configured to apply acompressive force to the shaft 302 of the hook member 301 when it iscompressed, thereby further locking the construct, such as lockingrotation of the construct. Still further, in some embodiments the headportion 303 is non-circular and partially passes through the aperture255B of the second clamp member 254B. In some such embodiments, thewasher member 312 engages the non-circular profile of the head portion,and via the at least one rib 214 prevents rotation of the hook member301, and therefore the bone anchor 350 captured in the arcuate channel305.

As described above and shown in FIG. 28, the particular orientation andposition of the clamp 300 is determined by which particular channel orgroove of the ribbed or slotted surface of the second clamp member 254Bis engaged by the at least one rib 314 of the washer member 312. Theparticular orientation and position of the clamp 300 may thereforedepend upon the particular position and orientation of the bone anchor350.

In some embodiments, as indicated in FIG. 28, the bone anchor 350 mayinclude a force F that biases the bone anchor 350 in a direction awayfrom the second clamp member 254B. Such a force may result from the useof the bone anchor 350 as a manipulation tool for the bone to coupledthereto (i.e., use of the bone anchor 350 as a joystick). In such ascenario, the clamp 300 may primarily prevent the bone member 350 frommovement resulting from the bias force F, as shown in FIG. 28. Forexample, the clamp 300 may not prevent movement of the clamp 300 in adirection towards the second clamp member 254B, and therefore the clamp300 may not prevent the bone anchor 350 from movement in a directiontowards the second clamp member 254B.

FIG. 29 shows an exemplary construct 375 including the exemplarytargeting guide 200, the exemplary clamp 300 and exemplary bone anchorsapplied to target fusion bones. In particular, the complete construct375 is applied to the capitate B1, hammate B2, lunate B3 and triquetralB4 bones of the wrist. As shown in FIG. 29, the exemplary fusion implant210 is implanted in a cavity that spans the capitate bone B1 and thehammate bone B2. The exemplary fusion implant 210 is positioned suchthat the first internally threaded aperture 218A and the firstnon-threaded aperture 220A is positioned within the capitate bone B1,and the second and third internally threaded apertures 218B, 218C andthe second non-threaded aperture 220B are positioned within the hammatebone B2. Also, because the fusion implant 210 is coupled to theoutrigger member 280, the fusion implant 210 is in the first or “proper”predetermined orientation with respect to the targeting instrument 200.

As the fusion implant 210 is in the “proper” orientation with respect tothe targeting instrument 200, a first bone anchor 272A has been passedthrough the first bone anchor aperture 252A, into the capitate bone B1,and finally through the first non-threaded aperture 220A. Similarly, asecond bone anchor 272B has been passed through the second bone anchoraperture 252B, into the hammate bone B2, and finally through the secondnon-threaded aperture 220B. In such a configuration, the capitate boneB1, hammate bone B2 and the construct 375 (fusion implant 210 andtargeting instrument 200) are fixed or locked with respect to oneanother.

The lunate bone B3 is also locked or fixed to the construct 375, andtherefore the capitate B1 and hammate B2 bones, through the clamp 300and joystick bone anchor 350. As shown in FIG. 29, the joystick boneanchor 350 is implanted into the lunate bone B3 and used to repositionthe lunate, such as to an anatomical position. For example, the joystickbone anchor 350 may have been used to position the center of the lunatebone B3 about 11 degrees radial to the capitate-hammate articulationlongitudinal line. Once the lunate bone B3 has been repositioned orreoriented, the clamp 300 was used to lock the position and orientationof the lunate bone B3 with respect to the targeting instrument 375, andthus the capitate bone B1, hammate bone B2 and fusion implant 210 aswell. In such a configuration, the construct 375 can be used to drillapertures via the at least one guide member 265 through the capitate B1,hammate B2, lunate B3 and triquetral B4 bones to the internally threadedapertures 218A-C of the fusion implant 210. As the construct 375 isfixed with the capitate bone B1, hammate bone B2 and lunate bone B3 viathe bone anchors 272A, 272B, 350, the position and orientation of thecavities formed by the drilling process can be assured. One the cavitiesto the to the internally threaded apertures 218A-C have been formed, thefusion members 50 described above can be used to draw the capitate B1and lunate B3 bones together, and the hammate B1 and triquetral B4 bonestogether such that they abut each another. Further, depending upon thelevel of rotation of the fusion members 50, the fusion members 50 mayapply a compressive force to the joint between the capitate B1 andlunate B3 bones, and the hammate B1 and triquetral B4 bones.

A surgical method for fusing target fusion bones will now be described.The method utilizes some of the devices, instruments, features, aspects,components and the like described above, and therefor reference will bemade to the above described embodiments, such as the illustratedembodiments presented in the figures and discussed above. However, suchreferences are made for exemplary purposes only and are not intended tolimit the surgical method beyond the specifically recited steps.Further, the surgical method may be discussed under the umbrella ofparticular bones, but such an application is not intended to be limitingand the method described herein may be used or conducted with bones orother tissue not specifically discussed herein without departing fromthe spirit and scope of the surgical method.

Assuming four adjacent, but spaced, bones were targeted for fusion, afusion implant, such as fusion implant 10, and fusion members, such asfusion member 50, may be used to fuse the bones to one another. Forexample, in reference to the bones of the wrist, the hammate, capitate,lunate ad triquetral bones may be fused to one another. In order toimplant the fusion implant 10 into the bones, an implant cavity willfirst be formed into two of the adjacent bones. For example, in someembodiments the hammate and capitate bones are dilled out to form thecavity. The method of forming the cavity may include usage of the abovedescribed guide clamp 100.

In some embodiments, a dorsal midline incision is made in the wristthrough the third compartment, retracting the EPL tendon. In someembodiments, the capsule may then be incised in a longitudinal directionand elevated both radially and ulnarly. In some such embodiments, thescaphoid is excised with a ronguer. The distal aspect of the lunate andtriquetral bones and the proximal aspect of the capitate and hammatebones may then be decorticated.

At such a junction, the longitudinally extending second bone abutmentsurface 112 of the bone abutment member 110 of the second arm 104 of theguide clamp 100 may then be placed on the dorsal side of the hammatebone, and the projection 116 of the laterally extending third boneabutment surface 11 may be placed in the detent commonly found on themedial side of the hammate bone (e.g., the tubercle/depression locatedat the capitate/trapezoid articulation) that opposes the capitate bone,as shown in FIG. 18. In some such embodiments, the guide member 106 ofthe first arm 102 is positioned adjacent the lateral side of thecapitate bone that opposes the hammate bone, as shown in FIG. 18. Theposition of the guide member 106 may then be adjusted such that theguide member 106 is located in an intermediate position in thedorsal-palmar direction, or slightly a more palmar position, such thatthe longitudinal axis X3-X3 of the guide member extending to theprojection 116 is located in a intermediate position through the hammateand capitate bones in the dorsal-palmar and distal-proximate directionto ensure the longitudinal axis X3-X3 passes through a significantportion of both the hammate and capitate bones, as shown in FIG. 18. Forexample, the longitudinal axis X3-X3 of the guide member 106 may haveabout 10 degrees to about 15 degrees of tilt an ulnar proximal palmardirection.

Once a particular location of the guide member 106 is determined, a usermay squeeze the manually engageable members 122A, 122B of the first andsecond arms 102, 104 to translate the guide member 106 towards theprojection 116 of the third bone abutment surface 11. In someembodiments, such translation may force a spike of the first boneabutment surface 108 of the guide member 106 into the capitate bone, asshown in FIG. 18. In some embodiments, such translation may force thefirst bone abutment surface 108 into abutment with the capitate bone, asshown in FIG. 18. Once the first bone abutment surface 108 is positionedinto and/or in abutment with the capitate bone, the first and secondratcheting members 124A, 124B of the arms 102, 104 may lock the positionof the first bone abutment surface 108 with respect to the capitatebone, as shown in FIG. 18.

In some embodiments, a drill including a drill bit sized and shaped tobe received within the aperture or tube of the guide member 106 isinserted in the guide member 106 and the drill is plunged into thecapitate and hammate bones. In some such embodiments, the guide member106 is sized and shaped to orient and position the drill such that thedrill creates an implant cavity in the capitate and hammate bones thatis aligned along the longitudinal axis X3-X3 of the guide member 106.The cavity may be formed such that the cavity extends through thecapitate and at least partially through the hammate bones. After thecavity is formed, the first and second ratcheting members 124A, 124B ofthe arms 102, 104 may be disengaged and the guide clamp 100 removed fromthe capitate and hammate bones.

Once the implant cavity in the capitate and hammate bones is formed, afusion implant 10, 210 may be prepared for insertion into the cavity.The method for preparing the cavity may include the step of coupling thefusion implant 10, 210 to an instrument, such as the targetinginstrument 200, in a predefined first or “proper” orientation, as shownn FIGS. 19-21. The predefined orientation may result from the profile ofthe second end 14, 214 of the fusion implant 10, 210 and/or the profileof the end of the outrigger member 280. In some embodiments, couplingthe fusion implant 10, 210 to the targeting instrument 200 includes thestep of orienting the fusion implant 10, 210 and the outrigger member280 of the targeting instrument 200 with respect to each other such thatthe first end 12, 212 of the fusion implant 10, 210 is properly matedwith the end of the outrigger member 280 of the targeting instrument200. In some such embodiments, such a step may include orienting thefusion implant 10, 210 with respect to the outrigger member 280 suchthat the first end 14, 214 of the fusion implant 10, 210 and the endprofile of the outrigger member 280 mate and a visual or tactileindication indicating a incorrect orientation is not present. In someembodiments, such an orienting step may include orienting the fusionimplant 10, 210 with respect to the outrigger member 280 such thatlongitudinally extending apertures in the first end 14, 214 of thefusion implant 10, 210 and the outrigger member 280 are aligned.

In some embodiments, once the fusion implant 10, 210 and the outriggermember 280 are mated in the first or “proper” predefined orientation,the fusion implant 10, 210 and the outrigger member 280 are selectivelycoupled to each other in the orientation. Coupling the fusion implant10, 210 and the outrigger member 280 in the predefined orientation mayinclude the step of inserting a threaded tightening bolt 282 into theoutrigger member 280 aperture and the aperture 40, 240 of the fusionimplant 10, 210. The threaded tightening bolt 282 may be rotatablyinserted into the aperture 40, 240 of the fusion implant 10, 210, andthe further rotated to pull the first end 14, 214 of the fusion implant10, 210 into the end of the outrigger member 280 to selectively couplethe fusion implant 10, 210 and the outrigger member 280.

Coupling the fusion implant 10, 210 and the outrigger member 280 to oneanother in the first orientation may include the step of aligning theinternally threaded apertures 18A-C, 218A-C of the fusion implant 10,210 with apertures 268A-C of the guide members 265 of the targetinginstrument 200, such as aligning the axes Z1-Z1, Z2-Z2 of the internallythreaded apertures 18A-C, 218A-C of the fusion implant 10, 210 with theaxes Z3-Z3, Z4-Z4 of the apertures 268A-C of the guide members 265 ofthe targeting instrument 200, as shown n FIGS. 19-21. The coupling stepmay also include aligning the non-threaded apertures 20A, 220A, 20B,220B, with the first and second bone anchor apertures 252A, 252B of thetargeting member 250 of the targeting instrument 200, such as aligningthe axes Y1-Y1 of non-threaded apertures 20A, 220A, 20B, 220B, with theaxes Y2-Y2 of the first and second bone anchor apertures 252A, 252B ofthe targeting member 250 of the targeting instrument 200, as shown nFIGS. 19-21.

Once the fusion implant 10, 210 and the outrigger member 280 are coupledto one another, the fusion implant 10, 210 may be inserted into theimplant cavity formed in the hammate and capitate bones, as shown inFIGS. 22, 23 and 29. In some embodiments, the fusion implant 10, 210 ispositioned in the implant cavity such that the first internally threadedaperture 18A, 218A and the first non-threaded aperture 20A, 220A arepositioned within the capitate bone, and the second and third internallythreaded apertures 18B, 218B, 18C, 218C and the second non-threadedaperture 20B, 220B are positioned within the hammate bone. The positionof the fusion implant 10, 210 in the implant cavity in the hammate andcapitate bones may be checked via fluoroscopic visualization.

With the fusion implant 10, 210 properly positioned within the implantcavity in the hammate and capitate bones, the targeting instrument 200,and therefore the fusion implant 10, 210, can be rotated about thelongitudinal axis X-X of the fusion implant 10, 210 and into anorientation such that lunate and triquetral bones are positioned betweenthe fusion implant 10, 210 and the at least one guide member 265, asshown in FIGS. 22 and 23. More specifically, the targeting instrument200 may be positioned such that the axes Z3-Z3, Z4-Z4 of the guideapertures 268A-C of the guide member 265 pass through intermediateportions of the lunate and triquetral bones in the dorsal-palmardirection. In some embodiments, the targeting instrument 200 may bepositioned such that the outrigger member 280 is perpendicular to thelongitudinal axis of the carpus, or flexed no more than about 5 degrees.Once the targeting instrument 200 is properly positioned with respect tothe hammate, capitate, lunate and triquetral bones, the positioningand/or orientation of the targeting instrument 200 may be fixed to atleast one of the hammate, capitate, lunate and triquetral bones. Forexample, in one embodiment once the targeting instrument 200 is properlypositioned a first bone anchor, such as a k-wire, is inserted throughthe first bone anchor aperture 252A of the targeting member 250, intothe hammate bone, and into the first non-threaded aperture 20A, 220A ofthe fusion implant 10, 210. Similarly, a second bone anchor, such as ak-wire, may be inserted through the second bone anchor aperture 252B ofthe targeting member 250, into the capitate bone, and into the secondnon-threaded aperture 20B, 220B of the fusion implant 10, 210. In thisway, the first and second bone anchors can couple or fix the targetinginstrument 200, fusion implant 210, hammate bone and capitate bone withrespect to one another.

The lunate bone may also be fixed to the targeting guide 200. In someembodiments, a third bone anchor 350 may be implanted into the lunatebone, and then used as a joystick to reposition the lunate. In someembodiments, the joystick bone anchor may be used to position the lunatebone in an anatomical position. For example, the third bone anchor 350may be used to position the center of the lunate bone about 11 degreesradial to the capitate-hammate articulation longitudinal line. In someembodiments, the third bone anchor 350 is used to reposition the lunatebone in the dorsal-palmar direction. Once the lunate bone has beenrepositioned, it may be fixed to the targeting instrument 200 tomaintain its new position. In some embodiments, the third bone anchor350 is secured to the targeting instrument 200 after it is used toreposition the lunate by a clamp 300. In some such embodiments, thethird bone anchor 350 is positioned within an inner portion of a hookmember 301 of the clamp 300, and a compression member 306 is rotatablycoupled hook member 301 and advanced through the hook member 301 tocompress the third bone anchor 350 between the compression member 306and an arcuate channel 305 of the hook member 301. In some suchembodiments, the hook member 301 is coupled to a second clamp member254B of the targeting member 250 of the targeting instrument 200. Thehook member 301 may be coupled to the second clamp member 254B by awasher 312 including a rib 214 configured to engage the second clampmember 254B, and a nut that compresses the washer 312 against the secondclamp member 254B.

In some embodiments, a fourth bone anchor is inserted in the triquetralbone, and the triquetral bone is repositioned using the fourth boneanchor as a joystick. After repositioning the triquetral bone with thejoystick fourth bone anchor, the fourth bone anchor may be fixed to thetargeting guide 200 to maintain the new position. The fourth bone anchormay be fixed to the targeting guide 200 in a substantially similar wayas compared to fixation of the third bone anchor 350 to the targetingguide 200. The primary difference between the fixations being the use ofthe first clamp member 254A, as opposed to the second clamp member 254B.

Once the targeting instrument 200 is fixed to at least the hammate,capitate and lunate bones via the bone anchors, fusion member cavitiesmay be formed in the bones to the internally threaded apertures 18A-C,218A-C of the fusion implant 10, 210. Before the fusion member cavitiesare formed, a depth gauge may be inserted into the at least one guidemember 256 to determine the depth of the internally threaded apertures18A-C, 218A-C of the fusion implant 10, 210, and therefore the properlength that the cavities should be drilled to and how far the fusionmembers should be advanced into the cavities. In some embodiments, afterthe depth gauges are used to determine the proper lengths of the fusionmember cavities, particular drill bushings 270A-C configured to stop thedrill drilling process at the correct depths are inserted into the guideapertures 268A-C of the guide members 256. In some embodiments, a drilland drill bit are guided by the drill bushings 270A-C to created fusionmember apertures in the hammate, capitate, lunate and triquetral bonesto the internally threaded apertures 18A-C, 218A-C. In some suchembodiments, the fusion member apertures may be spaced about 2millimeters or less from the internally threaded apertures 18A-C,218A-C.

In some embodiments, once the fusion member apertures are formed, thefusion members 50 are inserted and driven into the cavities. In someembodiments, the fusion members 50 are rotatably inserted into thecavities such that the first externally threaded portion 56 includingthe first thread lead is threadably coupled to the internally threadedapertures 18A-C, 218A-C of the fusion implant 10, 210. In some suchembodiments, the second externally threaded portion is engaged witheither the capitate or triquetral bones, depending upon which cavity isused. In some embodiments, the non-threaded portion spans the jointbetween the lunate and capitate bones, or the hammate and triquetralbones, depending upon which cavity is used.

In some embodiments, insertion of a fusion member 50 into the firstinternally threaded aperture 18A, 218A substantially eliminates thespace between the adjacent surfaces of the capitate and lunate bones. Insome such embodiments, the fusion member 50 applies a compressive forceto the joint between the adjacent surfaces of the capitate and lunatebones. In some embodiments, insertion of a fusion member 50 into thesecond or third internally threaded apertures 18B, 218B, 18C, 218Csubstantially eliminates the space between the adjacent surfaces of thehammate and triquetral bones. In some such embodiments, the fusionmember 50 applies a compressive force to the joint between the adjacentsurfaces of the hammate and triquetral bones.

One advantage of the embodiments discussed herein of the presentinvention is that the fusion implants and associated fusion members drawadjacent spaced bones together. Another advantage of the fusion implantsand associated fusion members of the embodiments discussed herein isthat they apply a compressive force to the joint of abutting bones.Another advantage of the fusion implant, instruments and methodsdiscussed herein is that they provide consistent, repeatable alignmentbetween the fusion member, target fusion bones and fusion processes,such as securement and drilling processes. Another advantage of thefusion implant, instruments and methods discussed herein is that thetarget fusion bones are secured such that a predetermined orientation orpositioning of the fusion implant and associated fusion members isconsistently achieved.

The fusion implants, fusion members, fusion devices, constructs,instruments, clamps and methods disclosed herein may include one or morefeatures of the fusion implants, fusion members, fusion devices,constructs, instruments, clamps and methods disclosed and/or claimed inthe following co-pending patent application that is assigned to theassignee of the present invention and is hereby expressly incorporatedby reference in its entirety as part of the present disclosure: the U.S.Patent Application No. 13/982,152 filed on even date herewith, andentitled “Lower Extremity Fusion Devices and Methods.”

As may be recognized by those of ordinary skill in the pertinent artbased on the teachings herein, numerous changes and modifications may bemade to the above-described and other embodiments of the presentinvention without departing from the spirit of the invention as definedin the claims. For example, the particular devices, instruments,constructs and methods discussed herein with respect to particular bonesmay be used with other bones or tissue to achieve advantageous fusion.As another example, particular aspects or features described orillustrated herein as integral may be made from individual separatecomponents. Similarly, particular aspects or features described orillustrated herein as individual separate components may be combinedinto an integral unit. As another example, the threading describedherein may take any thread form known in the art that differs from thedescribed or illustrated threading. As another example, any aspect ofthe devices discussed herein that may be temporarily or permanentlyimplanted into the body of a patient may include a texture, coating,surface finish or the like to facilitate coupling of the aspect with thepatient. As another example, the fusion members may include at least oneaperture configured to facilitate other fusion members from attaching orcoupling thereto. Therefore, the implants, fusion devices or constructsdisclosed herein may include at least one fusion member coupled to atleast one other fusion member. As yet another example, the fusionimplants, fusion members, fusion devices, constructs, instruments andmethods discussed herein may be configured to facilitate fusion of morethan two bones, whether naturally adjacent or not. For example, theimplants may be configured for implantation, at least partially into twoor more bones. Similarly, for example, the fusion members may beconfigured to pass through, at least partially, two or more bones. Asanother example, fusion devices, constructs, instruments and methodsdiscussed herein may be configured for use with one fusion member, ormore than one fusion members, such as more than three fusion members. Assuch, the number of internally threaded apertures disclosed herein maydiffer. Further, the fusion devices, constructs, instruments and methodsdiscussed herein may be configured with implants with non-threadedapertures for coupling bone anchors through at least one bone andthrough the non-threaded aperture to stabilize the implant with the atleast one bone. As another example, the targeting instrument disclosedherein may be configured to interact with, and include, a bone anchorclamp.

Accordingly, this detailed description of the illustrated and exemplaryembodiments of the present invention is to be taken in an illustrative,as opposed to a limiting sense.

What is claimed is:
 1. A surgical instrument for use in obtaining bonefusion in an upper extremity of a patient, the instrument comprising: afusion implant including a first end, a second end and a body extendinglongitudinally therebetween defining a first axis, the body including atleast one aperture extending laterally therein defining a second axis; atargeting member including at least one arm, at least one bone fusionmember aperture configured to receive a bone anchor therethrough, and atleast one clamp member configured to securely couple with a bone anchormember clamp, the at least one clamp member defining a first sidesurface, a second slotted side surface and an aperture extending throughthe clamp member from the first side surface to the second slotted sidesurface, said second slotted side surface including at least one slotwhich includes a section that is spaced apart from said aperture of saidat least one clamp member; at least one guide member coupled to the atleast one arm of the targeting member and including an apertureextending through the at least one guide member defining a third axis;and an outrigger member coupled to the at least one arm of the targetingmember and securely removably coupled to the first end of the fusionimplant in a first orientation of the fusion implant, wherein theoutrigger member and the at least one guide member are configured suchthat the second axis of the bone fusion member aperture of the fusionimplant and the third axis of the aperture of the at least one guidemember are substantially aligned in the first orientation of the fusionimplant.
 2. The surgical targeting instrument of claim 1, wherein the atleast one arm of the targeting member includes at least a first armextending from the targeting member to the outrigger member, and asecond arm extending from the targeting member to the at least one guidemember.
 3. The surgical targeting instrument of claim 2, wherein thefirst arm and the second arm are configured to space the outriggermember and the at least one guide member from each other along the firstaxis of the fusion implant and along the third axis of the aperture ofthe at least one guide member.
 4. The surgical targeting instrument ofclaim 1, wherein the outrigger member and the first end of the fusionimplant are configured to be securely removably coupled to one anotherin only the first orientation.
 5. The surgical targeting instrument ofclaim 1, wherein the outrigger member and the first end of the fusionimplant are configured to provide a visual or tactile indication whenthey are coupled to one another in an orientation different than thefirst orientation.
 6. The surgical targeting instrument of claim 1,further including at least one bone anchor clamp configured toselectively couple to the at least one clamp member and a bone anchor.7. The surgical instrument of claim 1, wherein the body of the fusionimplant includes a substantially smooth outer surface, and wherein thebody of the fusion implant includes at least two non-threaded aperturesextending laterally therethrough from a first side of the body to asecond side of the body and at least two internally threaded aperturesincluding a first thread lead extending laterally through the body froma third side of the body to a fourth side of the body.
 8. The surgicalinstrument of claim 7, wherein the at least two threaded aperturescomprise a first threaded aperture proximate the first end and angledwith respect to the longitudinal axis of the body such that it definesan axis that angles away from the first end as it extends from the thirdside to the fourth side, and a second threaded aperture proximate thesecond end and angled with respect to the longitudinal axis of the bodysuch that the second threaded aperture defines an axis that angles awayfrom the second end as it extends from the third side to the fourthside.
 9. The surgical instrument of claim 8, further including at leasttwo longitudinally extending bone fusion members including a tip, a headand a shank extending longitudinally between the tip and the head, theshank including: a first externally threaded portion adjacent the tipincluding the first thread lead and being otherwise configured to coupleto the at least two threaded apertures of the body of the fusionimplant; a second externally threaded portion adjacent the headincluding a second thread lead that is less than the first thread leadand an external taper extending from the head to the tip; and anon-threaded portion extending between the first and second externallythreaded portions.
 10. The surgical instrument of claim 8, wherein thebody of the fusion implant includes a third internally threaded apertureadjacent the second internally threaded aperture, the third internallythreaded aperture extending laterally through the body and defining anaxis that is substantially parallel to the axis of the second internallythreaded aperture.
 11. The surgical instrument of claim 7, wherein theat least two non-threaded apertures of the body define substantiallyparallel axes.
 12. The surgical instrument of claim 7, wherein thefusion implant is substantially cylindrical, and the first and secondsides of the body are spaced about 90 degrees from the third and fourthsides of the body about the longitudinal axis.
 13. The surgicalinstrument of claim 7, wherein said at least two internally threadedapertures include said at least one aperture defining said second axis,one of said at least two non-threaded apertures defining a fourth axis,said second axis and said first axis defining a plane, said fourth axisbeing substantially normal to said plane.
 14. The surgical instrument ofclaim 1, wherein the targeting member includes a pair of the clampmembers extending from differing portions of the targeting member. 15.The surgical instrument of claim 1, wherein at least a portion of thesecond slotted side surface of the at least one clamp member is arcuate.16. The surgical instrument of claim 1, wherein the at least one bonefusion member aperture of the targeting member defines an axis, andwherein the slots of the second slotted side surface of the at least oneclamp member extend along the direction of the axis of the at least onebone fusion member aperture.
 17. The surgical instrument of claim 1,wherein the second slotted side surface of the at least one clamp memberfaces laterally away from the at least one guide member.